(http://i1108.photobucket.com/albums/h408/7Ambo707/2x12au7schematic001.jpg) I just put this amp back together in a blues jr. cab. I will post video asap. Sounds ok and is loud enough to kill an open mic. great for at home playing. I am guessing 2 or 3 watts but not real sure. I bet the smart guys on here could figure it out. smps is putting out 200 volts before the r/c filter. Feel free to redraw the schematic and post/build sell whatever with my blessing. Just do the right thing and mention my name in the inspiration section as I rightfully stole these ideas from Doug H. and Rick Holt aka Frequency Central. Cheers and be safe, Greg
ps . output trans is hammond 125c using the 11k taps on the primary side.
can't wait for the soundclips!
any chance you try this with bass? ;D
uploading to youtube now 8) havent tried with bass yet but not sure how good it would sound as its in a guitar combo... I can try though. if it sounds good i will post a vid clip of it!
<iframe width="425" height="349" src="http://www.youtube.com/embed/rkhOqfyzdN4" frameborder="0" allowfullscreen></iframe>
I hope this works...demo vid.....
That sounds pretty decent... ;D
Just thinking out loud... It looks like you just paralleled the two 12au7's in the power stage... Would the same idea be possible in one of FC's submini amps? For example the use of two 6111's in the Superfly instead of one, for a higher wattage output. How would that affect the way the transformer is wired up?
Thanks! I think that would work as the principal is the same. You would need a transformer with half the primary resistance at that point. I suppose if you hooked up a 4 ohm speaker instead of 8 it would do the same thing in theory. I think thats right....check first.
Where is the grid return resistor for the upper output triodes? Also, your coupling capacitor to the output stage comes off the wrong side of the plate resistor and so does the coupling cap from the first stage to the second stage. If it works, you have something different in there from what you drew. BTW, is that a tone stack at the input to the second stage? I don't see any pots and there is nothing in a position to act as a simple volume control.
Sounds like the 11K taps are a bit high for a push-pull parallel triode output. I would expect the optimum to be about half of that. Some people drive reverb tanks from a single-ended 12AU7 and the impedance is on the order of 2500 ohms. PPP 12AU7's may be around 2500 ohms plate-to-plate, but I don't have actual figures. Triode output impedances should definitely be less that pentode or beam power tube impedances.
I would also advise a lot more capacitance at the input to the SMPS. A power converter is a negative resistance at the input since the internal feedback (if regulated) causes the current to increase when the voltage decreases.
You surely don't have preamp plates wired as shown, and no grid-leak will work only for a short while. More like this:
(http://i.imgur.com/w3mmQ.gif)
> Sounds like the 11K taps are a bit high for a push-pull parallel triode output
It's not way-wrong. Matchbook analysis: each 12AU7 section is 6K, a good load is twice or 12K, 6K per side, in class A (which this must work in) the P-P impedance rating is twice, so nominal 12K p-p. 11K is spot-on.
For cleanliness you might go higher: THD falls faster than power.
For small hard guitar you might go 6K-5K for less speaker damping.
yeah i pretty much hate drawing schematics for this reason, I stink at it. There is a volume after the tone stack and a master right before the pa that is the grid ground reference. They are 1 meg . Also yeah, the caps are in the right spot in reality....just not on the schematic :icon_redface: I will correct and repost tomorow if i can.
This is mine, I have added a valve caster to the beginning since this drawing, and some things have changed, but it may give you ideals. This is using 12V (30max) rated tubes
(http://dl.dropbox.com/u/14312589/FireampV1.jpg)
you can hear it here. I am not playing anything, just messing with how it sounds, so I can go back and tweak. this is through a Carvin 2x12 cab with Carvin speakers.
Skip the first min as I wait for tubes to warm up. Between my wife opening the garage door and the bread board it is not as clean as it could be
This is recorded using a cheep $60 aiptek camcorder, using its mike.
As for yours, you need grid leak as stated, the tubes will die a painful death with out them as the grid will need to get rid of the little current it collects from the cathode. do not exceed what the datasheet has for the tube though. I believe in class A it list 1m Ohm max in the datasheet.
Watched the video, sounds good.. most of it is the player, I was not sure how much that jalapeño like EQ would get you, I was thinking of adding it to mine.. cleans up nice..
do you have a link to that power transformer (voltage booster)?
I am assuming that you are taking heater voltage strait from the one spot. and is that a ~9 dc one spot?
I have a compactron (6af11) with two triodes and a pentode in the same tube, but I need to keep it at around 200v DC.. and I do not want to spend $60 on a transformer if I do not need to..
Great thread,, I will have to add this to my set of projects.
thanks
Quote from: iccaros on May 09, 2011, 02:11:05 AM
Skip the first min as I wait for tubes to warm up.
so how do we warm up the tubes?
heaters... heaters have to heat the cathodes to make them discharge electrons.
On bread board it took 30- 45 Seconds to heat up. with the two 12K5's in parallel they could take a min before they produce sound as they both need to conduct
It's a pitty you didn't try a class AB push-pull attempt, since you are using 2 12K5's anyway...
If you use push-pull, you get dynamic current draw ... chance of getting sag ... compression ...
and ... lethal voltages? at 12V-24V? I thought non-lethality was specific feature of these tubes?
Quote from: iccaros on May 09, 2011, 10:37:37 AM
heaters... heaters have to heat the cathodes to make them discharge electrons.
On bread board it took 30- 45 Seconds to heat up. with the two 12K5's in parallel they could take a min before they produce sound as they both need to conduct
so we just turn power on right?
Quote from: Steben on May 09, 2011, 11:22:18 AM
It's a pitty you didn't try a class AB push-pull attempt, since you are using 2 12K5's anyway...
If you use push-pull, you get dynamic current draw ... chance of getting sag ... compression ...
and ... lethal voltages? at 12V-24V? I thought non-lethality was specific feature of these tubes?
Zmbo is using 200V from a voltage step system. Mine is only 12- 24, but its best to be safe
also this is my first build, I have some 26A7GT which are push pull @ 27 volts .5 watt, so I will do a tube rectifier to get SAG. and I have some 12AL8's which in AB push pull are nice as they have a triode and pentode built in, so from a the phase inverter to the triode to push the power tube a bit more.. :)
Iccaros, the capacitors on the output tube cathodes will give you a high-frequency boost starting at 3290 Hz and above. You may want to increase the cap to reduce this frequency or remove the caps altogether if you have enough gain. Your coupling capacitance of 0.0022 µF gives you a low-frequency turnover of 72.4 Hz. You could afford to go up in capacitance a bit to bring this down. Is R5 really 220K? This would give you mere 24 microamps in that stage.
Quote from: amptramp on May 09, 2011, 01:02:16 PM
Iccaros, the capacitors on the output tube cathodes will give you a high-frequency boost starting at 3290 Hz and above. You may want to increase the cap to reduce this frequency or remove the caps altogether if you have enough gain. Your coupling capacitance of 0.0022 µF gives you a low-frequency turnover of 72.4 Hz. You could afford to go up in capacitance a bit to bring this down. Is R5 really 220K? This would give you mere 24 microamps in that stage.
@amptramp
Thanks for the input, I am lost on these calculations, I was pulling my hair out using load lines with these tubes, so I put a pot on each cathode and twisted until I liked, then measured and put in the closed resistor for the value I read. I really believe my issue are the bread boards, so I am putting this on turret to test, but this is my starting point.
as for the 220K cathode, it is, and it boost according to the oscope from 10's of millivolts to hundreds of millivolts and the next stage boost from that to 6 volts. These tubes are meant for boosting radio signals, so this is the values that gave me the cleanest signal, any lower I started to get blocking distortion with most other settings, when I put a pedal before to get more overdrive it just died... It may have been the breadboards causing this.
Caps, I am really lost on calculating tone values and what they should be. 2.2 is the largest I have right now with out going to 220uf so this is what I have, what would be a good value 6.8? with out caps the power section farts out into oscillation and blocking distortion, so the thought is they would stabilize current, these tubes at 30V are a little different than normal, they are very sensitive.
As for coupling I have a .01 in C3 right now, did not update the drawing.
I started out with 220K on the plates and 2.2k on the cathodes, this was really clean, but when I added another stage just got blocking distortion, with these settings I was able to add the valve caster in front if this to get dirty.
@all Sorry I am not intending to take over this thread, Just wanted to compare Zambo's 12V amp to mine to get ideals going. I really like his version of the firefly using the nexitube power supply. next payday I will have to get 2 of those boosters.
No problem with the calculations, R*C is a time constant. 1/(RC) is a frequency in radians/second where there are 2 pi radians in a cycle. Therefore, frequency is 1/(2 * pi * R * C). You can calculate this by hand or use the following link for a calculator:
http://www.muzique.com/schem/filter.htm
But you should confirm your first calculations by hand, just to make sure you don't become dependent on having someone else's algorithm available.
so 1/(2*3.14*22*2.2) = 0.00328832709647294035632312417381
so what does that mean? is that 3288 hz? or do I need to put capacitance in a different form?
Sounds nice, Greg!
11k is fine. I liked 22k for my Firefly 2x12au7's, since you have two of those in parallel, 11k makes sense.
Are you planning on mounting all that high voltage stuff on a board? It's kind of dangerous the way it is spider-wired right now. I assume that's a prototype (?).
yeah i am going to put it on a board and mount it. Its totaly a prototype. Also an exercise in counting ground loops. Kind of a wheres waldo ( ground loop) thing. Thanks doug!
It sounds really good. I keep looking at tube amps and would love to build a low wattage amp for bedroom use. It looks like it wouldn't cost that much to build either. Keep up the good work and let us see your revised layouts please. ;)
Revised schematic!
(http://i1108.photobucket.com/albums/h408/7Ambo707/revisedschematicfor2x12au7ppamp001.jpg)
please double check if you would, and thanks for the corrections already!
Quote from: zambo on May 10, 2011, 06:59:48 PM
Revised schematic!
(http://i1108.photobucket.com/albums/h408/7Ambo707/revisedschematicfor2x12au7ppamp001.jpg)
please double check if you would, and thanks for the corrections already!
Have you thought about putting 10K or so grid stoppers on the output tubes. While you do not seam to be getting any oscillation right now, changing tubes may make that an issue, Grid stoppers would not really change the sound but may make it more stable with different tubes.
if it starts to oscilate I will, but its so quiet i dont think it will need them. I may change the .022 coupling cap to a .01 to tame the bass farts a little. Either that or the slope resistor..not sure yet.
Quote from: zambo on May 10, 2011, 07:23:26 PM
if it starts to oscilate I will, but its so quiet i dont think it will need them. I may change the .022 coupling cap to a .01 to tame the bass farts a little. Either that or the slope resistor..not sure yet.
The .01 could roll off some of the low end, but your eq values look weird, not that I can do the math well :) The bass fart does not come over camera well, so I am not sure, I like the tone, but these values from the Jalapeño tone stack according to the calculator puts everything in the center and keeps the signal boosted over all
(http://dl.dropbox.com/u/14312589/ToneStack.png)
I used this app
http://www.duncanamps.com/tsc/ to look at this stuff, I am too dumb to do real math.. I am trying, but well as good as it gets sometimes.
(http://dl.dropbox.com/u/14312589/ToneStack%20Chart.png)
this is yours
(http://dl.dropbox.com/u/14312589/ToneStack%20Chart%202.png)
*** I have a question on your power supply, It says 65 milliamp max, I am wondering if its putting out enough and could that lead to not being able to put out bass as clearly as the treble. ? I wonder if we put two, one for preamp and one for power section? A >1 amp power supply should not have many issues with that. I have two on order to test..
Zambo
This is a first attempt at redrawing your schematic, Make it a little easier to edit when you have changes its in Visio so I am including that file so people can edit. I have not added the power supply yet, need some sleep, I am on travel to the east cost so my schedule is way off..
PDF
http://dl.dropbox.com/u/14312589/Twin-12AU7-AMP.pdf (http://dl.dropbox.com/u/14312589/Twin-12AU7-AMP.pdf)
PNG
(http://dl.dropbox.com/u/14312589/Twin-12AU7-AMP.png)
Visio
http://dl.dropbox.com/u/14312589/Twin-12AU7-AMP.vsd (http://dl.dropbox.com/u/14312589/Twin-12AU7-AMP.vsd)
This amp needs a cool name.. :)
Will add power tomorrow, just ask people to review so I can update what I messed up or what is not clear..
Need to add Pot connection numbers and a Attribution box...
Quote from: iccaros on May 10, 2011, 09:45:24 PM
this is yours
(http://dl.dropbox.com/u/14312589/ToneStack%20Chart%202.png)
Looking at that EQ curve, that could explain some of the bass fartiness he's experiencing.
@ iccaros - Thats super cool and appears to be correct to me! Thanks for drawing it up for real!! The bass response isnt as bad as I made it sound on the vid and its actualy nice for the clean settings. I put in an eq lift switch anyway so i can put a booster pedal in front with its own eq. I was debating the seperate 1363 for the preamp as well and have one to do it with. When I get some more time I will spider wire it for fun and see how it works. I like the reservoire caps and they seem to make this ps work quietly. I was getting whining before unless loaded just right. Thanks again for working on this. Its the most requested schematic of all the stuff Ive built so far and a bunch of people (including me) will appreciate your work on here.
I am going to post another vid with my trainwreck pedal in front of it soon here...Thanks again.
Cheers! Greg
!!!!!!!!!!!!!!!!This design is not tested... Build at your own Risk :icon_biggrin: :icon_idea:
Ok I updated the first drawing see above
For openion.. I can see where the tubes on this amp will draw too much current, leaving it current starved..
So How about doing this.... See warning...
(http://dl.dropbox.com/u/14312589/Twin-12AU7-AMP-altpower.png)
This works with a lM317... :) like that is the same thing..
Two SMPS *might* be asking for heterodyning........
Quote from: frequencycentral on May 12, 2011, 02:26:10 AM
Two SMPS *might* be asking for heterodyning........
I won't as for that then :icon_biggrin:
but seriously, could this be avoided by placing an bypass after the power supply, or is the nose on ground? So say we put a 200K in parallel with C8 and C11?
or what ever the frequency range is? This may be adding way too much work.
I ask because I have some tubes like the 6111, that have a 160 volt max plate. which is too close to line power in for most transformers, as rectifying 120v (using a 12V transformer backwards for 12 in 10 out) 120*1.41 = 168 volts. maybe I am way over worried, and one is enough for this.
Math.... :icon_cry:
100K @ 200v is (200/100000 = .002) 2ma per triode
but the power section
200/11K (?should this be half of either or both of these?)
is .0181
or 18ma per tube in the output section
18 * 4 = 72 MA for the power section
if impedance is halved (200/5.5k) = 36 ma per tube
Either way this more than this power supply can put out 65ma
I know the system can not draw more than it can give.. so we hit a stage at which we are current limiting the output, or am I way off and have no clue what I am talking about?
what are smps? ;D
One way I have considered (but not tried) for getting more ma from a SMPS is to use just one HF oscillator (NE555 or MAX1771 etc), but use it to feed 2x MOSFETs, inductors, UF diodes and reservoir caps. Theoretically you could double the ma but without the risk of heterodyning of using 2x HF oscillators. It would probably be really fiddly to implement this with 2x 1363 PCBs, but still possible I guess, if you were to disable the oscillator of one board and use it as a slave to the first.
Rick is it possible to design one of these from scratch? Might be easier than trying to rework an existing pair. Building it as one unit would be neat. If we could get 250v and 60 ma for a power section we would have tha basis of a sweet 4 to 5 watt amp in a very small and light package. I am thinking it would be a sweet guitar case amp. :icon_wink:
Hey Rick i was wondering if you had ever bent your geniuse towards this thought.. http://www.diystompboxes.com/smfforum/index.php?topic=91565.msg781514#msg781514 . In series we could have like 400v at 50 ma if i understand it correctly :o that would make a heck of a screamin amp! Any thoughts on it?
Quote from: zambo on May 12, 2011, 12:20:21 PM
Rick is it possible to design one of these from scratch? Might be easier than trying to rework an existing pair. Building it as one unit would be neat. If we could get 250v and 60 ma for a power section we would have tha basis of a sweet 4 to 5 watt amp in a very small and light package. I am thinking it would be a sweet guitar case amp. :icon_wink:
Very possible, but I think you have to be a 'scientist' rather than whatever the hell I am. ;D I have a little knowledge of how they work, but I also know 'what I don't know'. I can build them, tweak them, but really I'm using them as pre-existing building blocks. When it comes to efficiency (which is where you'll get your high
ma) various factor come into play such as layout, very specific parts, parasitic inductance and capacitance and proximity to other stuff. The MAX1771 based SMPS is certainly capable of 100ma plus with the right components. Have a read of the 'High Current Experiments' paragraphs of this page:
http://www.desmith.net/NMdS/Electronics/NixiePSU.html
Nick Smith also contributed to our own forums MAX1771 development thread:
http://www.diystompboxes.com/smfforum/index.php?topic=79736.0
...as does the 1363's Taylor himself:
http://www.diystompboxes.com/smfforum/index.php?topic=79736.msg761723#msg761723
Cliff Schecht was designing something along the lines of what you suggest, I don't think he finished the project though:
http://www.diystompboxes.com/smfforum/index.php?topic=80165.0
Most SMPS designs out there are developed for nixie tubes, where audio artefacts are not an issue, and generally the
ma requirement is relatively small. I'm sure it's possible to design a nice high voltage high amperage SMPS for tube amp use. Sadly, I'm not the man to do it. But if someone else does, I'll be all over it.
Thanks for the info Rick. Very good reads. I sent taylor a pm asking if he knew of or was interested in designing/building such a device. Dont ask dont get right? Do you have any new amps since Obsession? I love your work. :)
I have some 6af11 compactrons. Which have two triodes and a pentode in the glass. the 65 ma of the smps should be enough (I estimate a draw of 35ma not counting heater) to get 2 -3 watts out (3.24 by the math .018 * 180) .
the squirrel monkey http://www.solorb.com/elect/musiccirc/squirrelmonkey1/ (http://www.solorb.com/elect/musiccirc/squirrelmonkey1/)
(http://www.solorb.com/elect/musiccirc/squirrelmonkey1/ChimpBox1.jpg)
Zambo you might be able to use one of these tubes, just adjusting your design, to create that Case amp.....
I bought 4 of these tubes on ebay for $12
i was reading about compactron amps on ax84 and saw that someone had mixed results with them. I havent tried but they seem interesting for sure. I love the idea of 2 pre and a power tube all in one envolope.
Quote from: zambo on May 12, 2011, 07:05:00 PM
i was reading about compactron amps on ax84 and saw that someone had mixed results with them. I havent tried but they seem interesting for sure. I love the idea of 2 pre and a power tube all in one envolope.
The ones I saw issues with had two pentodes in the same tube, sharing a cathode. I am not sure the issue, but I am sure its fixable. :)
I just got sockets in, I was going to use my 24.6 - 0- 24.6 backards and get 120 out from a 24v wall wart.. (should work yes?)
instead I have two of those SMPS on order.. Still need an output transformer to finish.. But I'll see if I can reproduce your tone with it..
Hey where can you buy output transformers on the cheap??? 30 bucks is alot to me.
Quote from: El Heisenberg on May 13, 2011, 01:57:23 PM
Hey where can you buy output transformers on the cheap??? 30 bucks is alot to me.
Whats a good price?
Quote from: amptramp on May 08, 2011, 09:46:22 PM
Where is the grid return resistor for the upper output triodes? Also, your coupling capacitor to the output stage comes off the wrong side of the plate resistor and so does the coupling cap from the first stage to the second stage. If it works, you have something different in there from what you drew. BTW, is that a tone stack at the input to the second stage? I don't see any pots and there is nothing in a position to act as a simple volume control.
Sounds like the 11K taps are a bit high for a push-pull parallel triode output. I would expect the optimum to be about half of that. Some people drive reverb tanks from a single-ended 12AU7 and the impedance is on the order of 2500 ohms. PPP 12AU7's may be around 2500 ohms plate-to-plate, but I don't have actual figures. Triode output impedances should definitely be less that pentode or beam power tube impedances.
I would also advise a lot more capacitance at the input to the SMPS. A power converter is a negative resistance at the input since the internal feedback (if regulated) causes the current to increase when the voltage decreases.
I started my own thread
http://www.diystompboxes.com/smfforum/index.php?topic=91606.0 (http://www.diystompboxes.com/smfforum/index.php?topic=91606.0)
I just realized there is a .0022uf 1kv cap that goes from the right half to the left half of the ot on the primary side or on pins 1 and 6 of the power tube closest to the ot. I dont really know how to update it but its a pretty important cap.
Quote from: zambo on May 13, 2011, 10:06:21 PM
I just realized there is a .0022uf 1kv cap that goes from the right half to the left half of the ot on the primary side or on pins 1 and 6 of the power tube closest to the ot. I dont really know how to update it but its a pretty important cap.
Updated.. Check the drawing on the (2) page, It should have updated to having the changes
almost, instead of going right to left it would have to go verticaly bridging the right and left sides of the ot primary. Thanks!
Quote from: zambo on May 14, 2011, 02:55:47 AM
almost, instead of going right to left it would have to go verticaly bridging the right and left sides of the ot primary. Thanks!
Ok,, how's it now?
I looked at the firefly this time :)
Thats it! Now it looks perfect. Thanks again!
Zambo
Can you read what your amp is pulling current wise? This would give us a better Ideal of needs. Or at the least be helpful for me
will do asap. where would I measure that? Across the.........b+ to ground from the ot primary centertap? positive lead on ct neg on ground? sorry to be dim....just still learning this stuff..
Just from the high voltage side.. just pull from the output of the power supply and the connect the meter between so that all current from the supply through the amp must flow through the meter. Ensure your meter is setup to read current (amps) which on mine means you must plug in differently.
(http://dl.dropbox.com/u/14312589/read%20Current.png)
Quote from: iccaros on May 12, 2011, 06:16:05 PM
I have some 6af11 compactrons. Which have two triodes and a pentode in the glass. the 65 ma of the smps should be enough (I estimate a draw of 35ma not counting heater) to get 2 -3 watts out (3.24 by the math .018 * 180) .
the squirrel monkey http://www.solorb.com/elect/musiccirc/squirrelmonkey1/ (http://www.solorb.com/elect/musiccirc/squirrelmonkey1/)
(http://www.solorb.com/elect/musiccirc/squirrelmonkey1/ChimpBox1.jpg)
Zambo you might be able to use one of these tubes, just adjusting your design, to create that Case amp.....
I bought 4 of these tubes on ebay for $12
I saw your Squirrel Monkey Before! Very nice, I really wanted to get one/build one when I saw it, just the idea of a single tube amp practice is somehow appealing.
Sorry that is not mine, I found it on the web.. I am planning on building it this year.. I have a Champ that died,,, well not mine a friends,, and he wants me to test this build using the Champ parts with this tube.. See what I can do..
Ok I have two Taylor edge SMPS http://www.tayloredge.com/ (http://www.tayloredge.com/) in, they ship fast, ordered on Friday got on monday..
In am going to attempt this once I get a transformer, I have been using 70volt line transformers, which I do not believe will cut it..
Also I need more resistors and caps.. The high wattages ones, I always seem short on. .
If you get the higher voltage 400+ caps you can always switch to a hammond 269ex power trans later if you like. Its a nice option to have. I used the small bear 250v caps in mine as thats what i had around. Looking forward to hearing your amp sir! sorry i havent measured the current yet on mine. I am building a proper board for the ps and caps. I also got side tracked building a seperate tube reverb :icon_eek: the good news is it works...it hums a little and I need to enclose it.....another thread I guess. :icon_rolleyes:
tube spring reverb or a Tube reverb no spring..
I got a bunch of 400 and 650 caps, but wrong values.. I did not lot of robotics for work so digital electronic take different caps.. so stocking up..
before you buy a ot check this out. http://tdsl.duncanamps.com/show.php?des=6V6GT so at 180 volts its only drawing 32ma at idle? do i have that right? You could have a 2 watt 6v6 amp running on a smps instead! I have a 6k6 now and I really like it I may change it to a 6v6 instead as it draws less ma and seems like I would get more bang from it. I am trying to figure out if we could run 2 in parallel for the same voltage but double the ma. them we could run 2 6v6 in se mode. small and LOUD. :icon_eek:
That is the same tube that is in the Fender champ (silver face)
It is a tough tube, fender runs them close to 300V... the JJ version is rated to 500V..
It is rated for 12 watts..
but @ 180 volts and .03 amps is close to 5 1/2 watts.
@ zambo
Where did you get 400K 5 watt resistors?
its a surplus store in santa rosa ca. electronics plus in san rafael ca. sells them and they ship as well if you need to order. they are pretty fast as well. kinda pricey for some stuff but no minimum order so thats cool.
Quote from: zambo on May 21, 2011, 10:07:43 PM
its a surplus store in santa rosa ca. electronics plus in san rafael ca. sells them and they ship as well if you need to order. they are pretty fast as well. kinda pricey for some stuff but no minimum order so thats cool.
I know what I was doing wrong, I fixed the schematic.. I had 400k not 400 ohm.. Let me tell you 400K 5w are rare.. 400ohm 5 watt not so much..
haha... good catch, i missed that one. yeah 400 ohm is gooder :icon_wink:
Quote from: zambo on May 18, 2011, 01:11:19 PM
before you buy a ot check this out. http://tdsl.duncanamps.com/show.php?des=6V6GT so at 180 volts its only drawing 32ma at idle? do i have that right? You could have a 2 watt 6v6 amp running on a smps instead! I have a 6k6 now and I really like it I may change it to a 6v6 instead as it draws less ma and seems like I would get more bang from it. I am trying to figure out if we could run 2 in parallel for the same voltage but double the ma. them we could run 2 6v6 in se mode. small and LOUD. :icon_eek:
!!!!! If I had all this stuff you guys have just layin around to play with, I'd have tried that 5 minutes before I posted that message!
I hope you do try that out. I already have a buncha 12au7s, and I ordered the SMPS a day or two ago. How long did it take to ship? I didn't get a confirmation email or anything just a paypal receipt.
Anyway, I don't have the output transformer yet. Im about to build 5 pedals in a row for a friend and I get to order a few extra parts for myself, I was thinkin of just spending it all on the output transformer...
But should I wait till Zambo tries this?? Id need a different output tranny. 2 X 6v6s!!!
Quote from: El Heisenberg on May 23, 2011, 02:49:56 PM
Quote from: zambo on May 18, 2011, 01:11:19 PM
before you buy a ot check this out. http://tdsl.duncanamps.com/show.php?des=6V6GT so at 180 volts its only drawing 32ma at idle? do i have that right? You could have a 2 watt 6v6 amp running on a smps instead! I have a 6k6 now and I really like it I may change it to a 6v6 instead as it draws less ma and seems like I would get more bang from it. I am trying to figure out if we could run 2 in parallel for the same voltage but double the ma. them we could run 2 6v6 in se mode. small and LOUD. :icon_eek:
!!!!! If I had all this stuff you guys have just layin around to play with, I'd have tried that 5 minutes before I posted that message!
I hope you do try that out. I already have a buncha 12au7s, and I ordered the SMPS a day or two ago. How long did it take to ship? I didn't get a confirmation email or anything just a paypal receipt.
Anyway, I don't have the output transformer yet. Im about to build 5 pedals in a row for a friend and I get to order a few extra parts for myself, I was thinkin of just spending it all on the output transformer...
But should I wait till Zambo tries this?? Id need a different output tranny. 2 X 6v6s!!!
A good line transformer would also work for SE.. It may saturate as there is no air gap. but this is PP so that would not matter, its would require figuring out the taps.. Parts express has 10 and 15 watt for $5 - $8, I would have to review what others have taught me and get an answer.
I tried the two 1363 smps in parallel and it hetrodynes so, no love on that one.....the single 6v6 with one smps works though and its a good 2 watts says duncan amp pages. I am still going to try it. I have the 6k6 amp but i neeed to rebuild it. it was one of my first amps and could use some tunning up and have some new tricks applied. As far as output trans goes. get athe biggest one you can afford within reason and with variable taps. you will always reuse it in something it seems. :icon_wink:
Eh, I'm gunna wait for iccaros to do the experimenting before I make a purchase. I don't have the stuff lying around or the resources to just buy stuff I ain't sure will work/ :(
I really want this design to be done!!
I orderd two of the SMPSs for some reason...
I have parts on order, but work Travel and my Masters program may push this back.. I do not have enough 12AU7 so I was going to try with 6111, I know Frequency Control already did a firefly with 6111, but this is a Push Pull Parallel firefly.. I have to look at what he used for a OT.. If I have to buy an OT it will be a few weeks...
Or maybe zambo. He brought up using the 6v6s
Quote from: iccaros on May 25, 2011, 12:39:12 AM
I have parts on order, but work Travel and my Masters program may push this back.. I do not have enough 12AU7 so I was going to try with 6111, I know Frequency Control already did a firefly with 6111, but this is a Push Pull Parallel firefly.. I have to look at what he used for a OT.. If I have to buy an OT it will be a few weeks...
The Superfly (6111, 6112 Firefly) uses a Hammond 125A ot, building one right now.
Quote from: Perrow on May 25, 2011, 01:16:48 AM
Quote from: iccaros on May 25, 2011, 12:39:12 AM
I have parts on order, but work Travel and my Masters program may push this back.. I do not have enough 12AU7 so I was going to try with 6111, I know Frequency Control already did a firefly with 6111, but this is a Push Pull Parallel firefly.. I have to look at what he used for a OT.. If I have to buy an OT it will be a few weeks...
The Superfly (6111, 6112 Firefly) uses a Hammond 125A ot, building one right now.
then I will have to wait... hard to do 22.5K to 8 ohms with a line transformer.
I may just build the Squirrel Monkey
I may end up using two smps one for pre and one for power. I will use split supply and caps etc. I hope it doesnt hetrodyne again. thats annoying. I muy run 3 12au7 in the power section though. will have to see if I can run that much ma with the 9 volt walwart. may have to use a 16 volt...hmm....the fun of it all :icon_smile:
Quote from: zambo on May 25, 2011, 12:54:28 PM
I may end up using two smps one for pre and one for power. I will use split supply and caps etc. I hope it doesnt hetrodyne again. thats annoying.
Which of Mother Nature's immutable laws are you planning to change? ;)
I plan on using a 12v 1A transformer. More current from the power tranny the better?
Quote from: zambo on May 25, 2011, 12:54:28 PM
I may end up using two smps one for pre and one for power. I will use split supply and caps etc. I hope it doesnt hetrodyne again. thats annoying. I muy run 3 12au7 in the power section though. will have to see if I can run that much ma with the 9 volt walwart. may have to use a 16 volt...hmm....the fun of it all :icon_smile:
I'm behind you.. :)
3 12au7s??
I just want as much volume as possible. So I'm still gunna wait till this developes more. Besides, I still don't wanna shell out that much money for one freakin part. The output transformer. Seems like alot of money for so few watts. A chip doesn't need an output tranny.
I'm starting leaning towards just getting some 6v6s and tryin to go that route... alone??
This might be neither practical or possible, but (in theory) couldn't you use two line transformers "in series"?
There'd sure be some efficiency loss but it could work.
Quote from: zambo on May 25, 2011, 12:54:28 PM
I may end up using two smps one for pre and one for power. I will use split supply and caps etc. I hope it doesnt hetrodyne again. thats annoying. I muy run 3 12au7 in the power section though. will have to see if I can run that much ma with the 9 volt walwart. may have to use a 16 volt...hmm....the fun of it all :icon_smile:
Save yourself a socket and run a 12BH7. It has a bit higher maximum anode voltage and power handling capability and can be used right down to 12 volts on the plate if needed. (I have a design somewhere for a 12 VDC grid dip meter using a 12BH7.) It is also less likely to be considered an "audiophile" tube, so pricing is reasonable. The only disadvantage is double the heater current.
As for not heterodyning, you either have to synchronize it or use just one supply. Hope is not part of the recommended design process.
That just makes me mad at hetrodyning :icon_evil: I might try the bh7 thing too. I mostly just want to see how far I can go with a 9volt walwart ampwise.
Zambo, did you see that smps I posted that with the changes at the end of the document put out 125ma ?
I saw it i just have no idea how to build it. Tubes i am passable with. anything else I usualy have a harder time making it work. It looks like i will have to get better at it though...
I am thinking of ordering some PCB, I have an eagle layout.. If I can get a good price I'll send you one to test..
Great little amps. I dont wanna let these designs go so im bumping em. I used both amps for this recording. Its to cassette tascamm 488 but it sounds ok
http://dl.dropbox.com/u/4685682/new.mp3
Cool sound clip El !! Thanks for sharing!