Not all that Fuzzy, the attacks seem...rough...
I tried 5089's and some 2n2222's and tin can [lower gain, and sounded lower gain] types, mostly the gain went up/down with Q swaps, otherwise no real change in the overall sound.
Plenty of boost.
I'm guessing the use of a 250k resistor between the collectors [the gain pot] instead of 350k might have something to do with it. Also a 250k volume pot...but that would mainly cause increased output.
That's cause you left the second .05 cap out, the Q1C > Q2B cap.
I used 4 pin sockets so I can try different value caps there, .0v/.0uf didn't sound too good.
.068uf is really cool, .022uf is thin on that side, ..no .047's around.
I used .015 and .0022 on either side of the tone control, still a thin sound available despite the .1uf input cap.
I also decided to make all the R's 440k.
All's well that ends well !!
Low battery trick makes it squashcomp/distort real neat.
The mix control seems to go from basic fuzz to Mangly Sizzling Distorto tones, exp. w a preboost, sounds smashed.
Useful Device !!! It's already in a pretty nice box, I'm going to fix it up some more and use it...Funny Fuzz is a blast to play!!!
when I built a Si version some years ago.
I picked reistor values for collector current and bias point.
The emitter Rs drop the gain because they are not bypassed
I like this circuit at about 2 to 2.5VDC at the collectors
http://www.diystompboxes.com/pedals/gusRitefuzz.gif
If you set the balance just right you can get an octave up.
" I like this circuit biased at 2-2.5v at the collectors"
Hey gus, does that go for a Germ version as well? I assume so. i have an original Fuzzrite that just sounds a bit TOO gaty and well 'crappy' fuzz. I know this crkt isn't the smoothest fuzz but I do think there's an issue with this one. I don't remember the vltgs right now but I think I had an extremely low Emitter vltg on Q2 where there should've been more.That may be backwards I don't remember but someone suggested "clipping" (argghhh!) the coupling cap before it to see if the vltg came up then. I have yet to try anything due to the way it's wired and those little Eyelets , you almost HAVE to cut leads!
anyway If SO on the vltgs for either version being relative, PETE could you post your Q1/Q2 vltgs so that I could use them as a reference!?
Someone also put it out there that my unit may not have been "original" , stock, because the Q1 and Q2 germaniums were of different type RCA part#'s
Well I have since verified that it IS INDEED original . There is one 2N404 i think and the other a 1613 or the like (??)
Don't mean to hijack your thread Pete!!! I just really would LOVE to get my old Mosrite up to snuff sounding as good as it can. I know R's can drift with time espec. those old 5% (or more :( ) carb comps that may already be so far off spec to begin with! so maybe I need to think about that too.
getting vltgs biased correct is my goal obviously
thanks
Cool thread Pete
I just took my fuzzrite out of my lineup coz it was a bit too harsh (ok for that "Satisfaction" "busted trombone" style fuzz, but not much else).
These ideas make me think I should re-bias or at least drop the batttery voltage and see if there's some smoother tones available.
You guys kill me with all your knowledge and endless experiementation. Keep it up.
cheers
I have not built a Ge or heard a Ge real one.
I built the circuit thinking how would I use Si transistors in that type of circuit.
One would need to measure a "good" Ge real one to work out how to clone it or even find out how the circuit was "designed" What collector voltages what gain of the transistor were both half the same or did they have different operating points as part of the design.
Q1
C .78 [That's low for this Si
B .55 [not far, .17 actually,
Q2
C .19 [Even lower than Q1 if that's possible, this Ge is cramped !
B .06 [Ground is exactly how far from base???<
What can you build if you have only 470k resistors?
Thanks for the RiteFuzz diagram Gus! That scheme for biasing looks much more conventional..I don't know what I'm going to do !
But ask a silly question !!!
Rippin Q1E, Q2E and Ground all apart looks difficult. Guiseppe wanted me to ask what happens if I were to leave the emitters connected, but introduce a resistance to ground 'under them'...lift the offboard ground and insert a small resistor there?
I kind of like the idea of having switchable collector resistors, 10k looks much more comparable/reasonable than 470k's [440k's In my case] for collector resistors ...I don't happen to have a 4pdt to build a Fuzzrite/Ritefuzz circuits in a box ..this would lift all the bias voltages by converting the bias scheme above/below the transistor...
Kind of surprizing anything even gets past those transistors with them biased so near to ground !
The thing does neat tricks though, and even approaches 'normal distorter' sound when mix is set mostly toward Q1, otherwise it can have a 'env fil' type of sweep sound for about 2 seconds after attack...sort of a secondary ghost tone...splatty/ducky/raunchy...yet somehow not terribly gatey...^should be tho...gets that 'Is that your amp breaking?' sound to it.
Does super job when pressed into Post-Octave Fuzz use.
Ge NpN in Q2 sounded different...
I put in switchable collector resistors...11k's / 440k's..one side of a DPDT.
Output shot up ten fold or so, Needs Smaller output pot value with ~10k on each collector. Still splatty and raunchy, smoother available as the mix knob is turned left.
I put a 100ohm between ground and each emitter...causing intractable oscillating. I split the emitters, now Q1 has a 120ohm, Q2 has 100ohm. This smoothed out the 10k's sound at collectors, further squelching the 440k on collector sound...
50k volume pot is a bit small for the 220k operation
680's on the emitters ~10k's on the collectors...
*680's on emitters 220k on the collectors...
*This is monster Fuzz, but needs help, it'll gate pretty good if I try to make sustain. However with a gain/clip circuit in front of it, really nice Fuzz is very easily tuned in. Attack has lots of variation, chords are very thick, the between attack/sustain there is a 'pronunciation' of notes...alot of gain and frequency variation in repsonse to input voltage/frequency.
And...it has pleased me very much indeed!...sounds really great with a faded battery, I think LM317 might be in order on this one.
The collector resistor selector switch imparts a rediculous amount of boost, best flipped when volume control is set @<1.
Thanks guys (Pete)
at mine looked like though! It was like that , so small of a B/E drop that It didn't look like much could be getting though as Pete said.
I do also remember noticing that mine gated a bit less was a bit smoother with a lower battery voltage in there. But it does fuzz and can sound "OK" if pushed with something but looking at these voltages I'd say there can be a major improvement
(input tranny)
Q1 C / 3.8v
B/ 100mV
Q2 C/ 75mv
B/ 58mv
YOU SEE WHAT I MEAN? even for Germanium that looks a problem to me at Q2.
As i said I was thinking of cutting the .05uf Cap between Q1 Coll and Q2 Base to see if the voltage came up. but have put that off. ; )
a question : One of the drawbacks of the old units is of course there is no input jack switching but instead an On/Off switch. Now I know most times if that is left on accidentally it's just gonna kill the battery BUT I wonder with the age on this thing (*mine dates to '65-66) enough times with that power left on, the old components and Germanium Trannies... What's the chances of something getting a bit flakey due to this?
My first suspect of this would be the 25uf Ducati cap with V- connected . there was corrosion on the batt/clip one time
Also I don't know if you're wiring your silicon vers. clones anyway resembling this BUT the DPDT wiring is very wierd on this thing!! take a look it's like this. I for the life of me can't understand how this thing switches effect/ bypass. GROUND effectively at 4 out of 6 lugs on a DPDT?!!?? does it like effectively 'kill' the transistor and give some type of 'buffered ' signal or something. It DEFINITELY not TB or Input always connected Switching.
in jack + crkt in - middle lugs tied together - jack ground -
out jack+ crkt out - and to Q1/2 Emitters - batt V+ and Ducati 25uf + side -
Q1 C / 3.8v
B/ 100mV
Your collector is higher than mine...on this one
Q2 C/ 75mv
B/ 58mv
YOU SEE WHAT I MEAN? even for Germanium that looks a problem to me at Q2. I think those look even more rediculous than what's acceptable, of course I had a flash like that when I measured the voltages I was getting...these are alot lower yet. You said Germanium...if there is no viable circuit problem causing this bias, I would begin to suspect a different tranny may exhibit a different [hopefully wider swing available] bias.
As i said I was thinking of cutting the .05uf Cap between Q1 Coll and Q2 Base to see if the voltage came up. but have put that off. ; )
Possible, this is an oldie, perhaps you could pull just one end...I kind of don't think that's it thought, what type of cap is it?
a question : One of the drawbacks of the old units is of course there is no input jack switching but instead an On/Off switch. Now I know most times if that is left on accidentally it's just gonna kill the battery BUT I wonder with the age on this thing (*mine dates to '65-66) enough times with that power left on, the old components and Germanium Trannies... What's the chances of something getting a bit flakey due to this?
Ge tranny's do have...someone say 25 years?...more? a shelf life...hit or miss depending on type of construction/environment etc.
My first suspect of this would be the 25uf Ducati cap with V- connected . there was corrosion on the batt/clip one time. Electrolytic caps have a shelf life more like 10 years, the better new ones anyway. It is a shame that you'd have to mess with your 'racing cap', Ducati, just to see if it's operational, I don't think you'd notice a tone difference changing cap brands there unless the Ducati is bad.
Also I don't know if you're wiring your silicon vers. clones anyway resembling this BUT the DPDT wiring is very wierd on this thing!! take a look it's like this. I for the life of me can't understand how this thing switches effect/ bypass. GROUND effectively at 4 out of 6 lugs on a DPDT?!!?? does it like effectively 'kill' the transistor and give some type of 'buffered ' signal or something. It DEFINITELY not TB or Input always connected Switching.
As far as the switching, I don't follow what you have there, or only good enough to say I'd think about scrapping that and using a true bypass scheme.
Scratch all that...this circuit is so easy to scratch up, I would just whip one up on perfboard and tweek that...
My RiteFuzz/~Fuzzrite thang got a good going over play-wise, there is a great 60's 'TONK' tone in it, needs a wash but isn't exactly dirty. It's amazingly adjustable really, setting that mix knob just right...
Smooth to splatty Fuzz, Booster w/Lotsa character sound available too...that mix knob works great!
I'm pretty sure I'm glad I couldn't find another .002 and subbed a .015uf instead at Q2's input.
And the 'small window' of swing room does a great job after a clipper, ...compression and frequency shifts and all...really cool stuff...great second stage of dual clipping!
I did pull the .05uf cap and Q2 Base away from one another and there was no impact on the C/B voltages of Q2. And also the Big Cermamic Disc tested good at about 41nan (It's a 20% tol)
Looking at the schematic now it seems that that Ducati cap is just there for " filtering?" purposes
It's just between -9v and Ground So if it was bad that wouldn't really cause any biasing problems would it. and if so it wouldn't be that Q1 is biasing but Q2 NOT.
I wish I could find a link to this original vers. schematic so I could post it. I was told once by RG that mine couldn't be original cause they didn't have 2N408 germaniums in them. Mine obviously is original though, not just from physical appearance but also the schem I have shows exactly as mine is Q1 2N2613 Q2 2N408 and all traces exactly as it is in that schematic.
As far as the switching, I don't follow what you have there, or only good enough to say I'd think about scrapping that and using a true bypass scheme.
Scratch all that...this circuit is so easy to scratch up, I would just whip one up on perfboard and tweek that
that would be fiine if I wanted to build one diy. I'm sure you understand that I want to get my vintage unit running properly. the fact that its' so simple of a circuit to me means all the more reason why it should be fairly easy get it biased right.
I hate to pull the other two leads of Q2 to do it, but I may consider your observation about germanium life and stick a good PNP(maybe even a silicon as Gus suggested once before) to see if it biases well! I don't know how much that would tell me though? seeing that it may have different biasing with the surrounding components but AT LEAST it should tell me if the 2N408 is bad!!
what's your thoughts? Thanks
Oh here's something else
I also checked the B/C resistor on that Q2 with the Base disconnected, and it is reading to within spec (1.1M and it's a 1Meg resistor)
However when I put the transistor Base back into the equation ( 1M R between C and B) all of sudden I get a 1K reading across that resistor.
Actually I think that's just the B/C resistance of the Tranny but shouldn't I get the larger 1Meg when it's across there?
Oh here's something else
I also checked the B/C resistor on that Q2 with the Base disconnected, and it is reading to within spec (1.1M and it's a 1Meg resistor)
However when I put the transistor Base back into the equation ( 1M R between C and B) all of sudden I get a 1K reading across that resistor.
The schematic I built from for the Fuzzrite showed all 470k resistors, where is/are these 1meg resistors in yours?
Actually I think that's just the B/C resistance of the Tranny but shouldn't I get the larger 1Meg when it's across there? Would seem so, in cases where I don't necessarily understand and suspect, I look for comparators to help me decide if...in this case if the transistor...here's what I'd do.
while base is disconnected measure B/C resistance, compare that to the B/C resistance of normal, known good Ge transistor...because 1k B/C resistance does not sound right.
I did that pete. I pulled out one of my old GT109's and first one I grabbed ( hfe of 57) I believe measured apprx 300k !!! would that be right? I've never measured R of a transitor unconnected.
YES I'd like there to be a pretty sure fire way of KNOWING that the tranny is "dead" (ouch!!) before I would go to the painful process of clipping it out of there and putting in a "SCAB" Germanium!!!
I did fire it up and play thru it too. It is just way to gated , lighter plucking on the strings it extremely splatty / gated. however the Fuzz really seems it would sound AWESOME, cause hitting the strings pretty heavy , it's not so gated and there's a real razor edge , almost ODish Fuzz!!!
And the 1Meg is the Base/ Collector R on Q2 , as I stated.
I think the Original Ge' Version is very different component -wise from the silicons. Either the silicon versions floating around the web OR the original "TZ82"(?)versions!
I wish I could Link to that schem of the original ( that's the 1965 era model btw) I think the one I have has 'fffworks' listed in the author/site line in the corner box . In case that tips anyone to "who/where" those schematics under that Name are on the net ; )
Another thing the Original has a "Depth" pot, not a "blend/mix" , I've not looked at the schems to see if they are wired the same. I think so actually
If I find a link I'll post it (that okay??)
OR Pete , PM me and I'll send it to you if I can find a harddrive copy!
Thanks again , you're being very helpful as usual.
Here it is , I found it!
http://eu11.stripper.jp/pulcino/blog/archives/cat_mosrite_fuzzrite.html
There's a nice little site here that has the ORIGINAL Ge' Fuzzrite schem AND PICS!!!! Hope I'm aloud to link to it ; O I'll remove it if not , aron.
I wish I'd have had this when I was discussing with R.G. and Gus about whether My unit was 'original' and never been tampered with! RG stated that " the original never used a 2N408 as it was mostly used in Logic cicuits in the day" Well I was pretty sure mine was stock cause by appearance little doubt the circuit was untampered But I never realized there were actual pics of them in the crkt on the web, else I'd have linked to them in that Old thread.l
Dragonfly also did one of his very nice Vero's of "this" Fuzzrite! That's the one I'd love to 'hear' some people trying! (hint hint PETE ; ) But please take a look at the schem and let me know what I should look at for attempt at biasing Q2 collector BEFORE I'd have to yank it from the board and test the crkt with a good PNP.
Hope this helps with ideas for biasing ,etc. my old unit
thanks ( maybe I should resurrect my old thread concerning this issue? it was only less than a year ago. )_
Analog,
I built Dragonfly's Si and Ge versions and they're completely different sounding circuits. The Si version is very compressed sounding where the Ge version is more open sounding and has that "room full of a million mosquitos" fuzz tone. I'm not certain if it working 100% because it only sounds good with the fuzz dimed. My first thoughts were that the Q1 isn't biased correctly but I won't have time to play with the circuit until after xmas. My Ge clone is not gatey or splatty, not compared to the silicon version anyway.
Chris
Thanks, yes I was aware of how different the two version were EVEN when i hijacked into this thread and asked about the voltages on the silicon version. BUT I was quite interested to hear that Pete also ran into the very strange almost miniscule C/B drop on this circuit.
I was just trying to get any ideas . however when I saw that Dragonfly had put together a vero of the EXACT correct original Ge version I now realize that If I"m not gonna find anyone with working experience with a vintage unit that ANYONE who's built his vero is who I need to talk to !!!
So hint hint, Could you give me your Q1 and Q2 Collector and Base vltgs please?
I hate to yank that original 2n408 Ge out of there unless I know I can't rebias it and that it's DEAD!!!
and hearing you say that you built it (all stock values I trust!, and yours is not splatty at all, I now also know that the hearsay is not neccessarily true that harsh and a bit splatty is just the way these sounded!!
thanks man I appreciate that little bit of info when you've a chance
analog kid
Thans for the lik to the other schematic. If I have some time I will think about troubleshooting ideas. I think leaving the stock unit alone until you know more is a very good idea
In the "new" schematic check the voltage across C2.
What I would do is build the fragment of the circuit around Q2 to understand Ges in this circuit, R4,R5,R3 and Q2 are all you need to measure voltages, try different Hfe transistors and make R3 100k, 220K, 330K, 470K etc... I would try 470K, 1 meg, 2 meg to start take some measurements with different hfe transistors and R3 values .
The 2nd stage works at much lower current than the first stage 22K first stage vs 147K 2nd collector resistors. Maybe your unit is working like it did when new.
thanks gus, no prob on the schem , If I wish I'd have posted that link when I started the thread concerning My Fuzzrite!
Across C2 is apprx 4.5v I say apprx cause I had a bit of a weak bat in there.
I don't know I can't imagine that it was like THIS when new, unless it was a Dud then ? I mean it's not just some minor gating/splattiness. which some old fuzzes just do. This is Major GATING!! And of course the fact that Q2 C/B are within 20mv of each other. ??? that just can't be ok
8miles is the only one i've heard of who owns or has built an original version Mosrite Fuzzrite. (I'm sure Dragonfly's built it too or I'd assume since he did the vero) so I 'm gonna have him check his voltages. BUT you're right... There's NO REASON not to just whip up this little circuit if nothing but for Test and research purposes! I don't know why I hadn't thought of that yet :icon_redface:
also another thing, looking at the schematic... Is there any reason that R4 would measure less than it's true value? of course testing with no power connected, I am getting a reading of 47k across R4 (*100k) ! it's between the 22k Q1 collector R and the 47k to Q2's collector. So I'm not seeing a reason why I shouldn't get the TRUE ohms across R4. NO? If so , I have been leaning towards this resistor as a possible problem for awhile now, Especially seeing that it's in direct line with Q2's collector, But as I said (and glad you agree) I just can't bring myself to do much tampering w/o know FOR SURE of the reason for why I do it!!! It took me alot of gumption to pull C4 from Q2 base.
Oh hold on now, I guess that if anything , having Too Low of a value in line with Q2's collector (R4) that this would allow a Higher Collector voltage right? well then that wouldn't be much of a problem to fix since the Collector is obviously Low Enough
thanks for the help here, I'll vero up that little circuit for testing today right after I finish decaling my A/DA Flanger clone!! Pics and Build report hopefully soon to come. I never do get round to doing those : 0
Hey Analog Dude,
I fired up my Ge Fuzzrite clone (built from Andy's layout) when I got home today and found that one side of the blend rips and the other sound terribly lame. Anyway, the good side maxed is a pretty cool sounding fuzz. Here are my readings: Hopefully this will guide you to getting yours working better, I consider my unit to be a small tweak away from being killer.
Transistors are Raytheon T59247
Q1
C=2.77v
B=0.1v
Q2
C=0.2v
B=0.08v
I can only assume the Q2 is horribly misbiased and might try to rebias it when I get a chance. Thuth is, that I know nothing about electronics so I just fumble my way through these builds and pray that they finally work in end after hours of trouble shooting. I work in stained glass and was looking for another place to stick my iron ;D
thanks man , I think I'm also gonna perf up this little circuit too to be able to 'play around' with HOW it biases . I hadn't thought of even doing that before even though I have the schematic ( and the original) BECAUSE I figured I have the real thing , what need do I have to rebuild it? Well , that's the need! To mess with the circuit w/o hacking up my vintage piece.
Anyway I like seeing those C/B vltgs on Q2.( as well as on Pete's Silicon unit) being very low biased collector. I do however have to believe that when that C/B drop gets much smaller ( yours is like 120mv right?) then that's when it's gonna start to get a bit gated. (??) Mine sitting at less than 20mv between Collector adn Base is surely got to be a problem.
another thing that would help me IF you don't mind is to put your meter across that 100k resistor (r4) in circuit, that's tied between the collector resistors. I'd like to see what resistance yours reads. If you get the full 100k value then I may have a wildly out of spec resistor.
thanks if you could do that as well
QuoteI work in stained glass and was looking for another place to stick my iron
Cool! I haven't heard that one before that's for sure. Whatever it took to get you into effects/electronics... I hope you get much use and enjoyment from it. Don't feel bad or discouraged that you fumble through the simplest of projects, The fact that it forces you to learn to troubleshoot properly and before you know it you WON'T be making the mistakes in the first place!! even on larger circuits. Have you worked ONLY with Veroboard btw?, perf? You've not done any pcb fabrication I assume? stripboard is definitely a unique medium, especially for learning to do your own layouts!
Thanks again man
from reading 8mileshigh last post about a new build it might be how the circuit was designed.
8mileshigh try a 470K and then a 2.2meg to start for the 2nd transistors base to collector resistor. Then try other values measure the 2nd collector voltage. For each R3 value write down the collector voltage, when you get the 2nd C about 2v I would give it a try.
thanks gus, this suggestion is intended for me as well I guess?
I see you obviously think that the B/C Resistor for Q2 is more important in this case for biasing the Coll.? and that you are suggesting trying both 470k (a much lower than stock) and a 2.2M ( a much higher than stock) Subbed for the 1M to see which way we need to go to 'bias' it , Right?
Matter of fact if a lower value would end up doing the trick here for bringing up the Collector then I could easily try a 470k or so in there w/o mucking about with the board!! this is something i can't do for the 100k (which is reading 47k)( R4 though since(as far as i know ) there's not a way to bet a higher value parallelling a 47k resistor. which....
Did anyone have an answer for me on why maybe that 47k thats seriesed between a 22k and 47k R's and between the Collectors MIGHT READ BELOW it's value of 100k?!
i hate to pull that resistor out only to find that it does indeed measure 100k after all!
analog kid Yes and no about "this suggestion is intended for me as well I guess?" 8mileshigh sounds like it is a new build and has no vintage value.
I agree with you about not doing anything to the effect until you are certain: However try jumpering (With jumpers) in a 1meg in parallel across the B to C resistor for 500K.
The value were about 1/2, 470K and X 2, 2.2meg
thanks gus, yeah I am going to parallel it with a 470k tonight, but no I'm not doing much til I know for SURE how things bias on it. Which I may have to learn from putting one together not even putting jacks on it to play though most likely(although I'm sure it'll be way too tempting! I've never put a circuit together w/o listening to it) Someone suggested that I drill a couple small holes aside the collector resistor(s) and CUT AWAY the existing resistor and solder in a trimpot to have the most precise control of biasing. I Say NO WAY to that!! I pretty much HAD TO try lifting the base Cap.
Mine actually still has most , a good bit , of the lettering on the enclosure although pretty weathered and pitted. that's sort of rare on these. the lettering comes off with the scratch of a fingernail. The way I heard it , in the beginning the Mosrite guy was pretty much producing these boxes " on his kitchen table" literally!! and i believe it
Don't mean to beat a dead horse but, No opinion on whether or not that R4 100k resistor SHOULD or SHOULDN"T actually measure it's full ohms value?!! I know often resistors will read different values depending on what they're connected to and need to be lifted on one end to get actual value. But in this ones case (seriesed) It doesn't seem to me any reason I shouldn't get 100k across it! (?) I only get 47k
Analog,
I thought you'd have to physically remove the resistor to get a proper reading of it. I did, however, get a 5.23v reading from touching both ends of the R4 with the volt meter if that's any help to you.
Gus,
Thanks for the suggestions, you may be right that it was designed like this but it just doesn't sound quite as good as I think it can. I was chatting with the guy on Ebay that makes those homemade looking Spooktone pedals & he says he knows a guy that built some of the old Mosrites in the day and said they were built with those low collector values on purpose. Maybe they came to the conclusion that the Ge didn't sound great & abandoned the circuit and went to the silicon version. I'll try rebiasing when I get a bit of free time, maybe in the next couple of days. My next challenge will be to try and record some soundclips.
Chris
Kind of like a dam for guitar signal...
Ie, a small window of bias on the transistors which distort, and increasingly clip and compress as input signal level increases.
Cuts [tear's?] away everything except a 'slice' of the input signal swing.
Anywhere just off bias line starts getting clipped. Clipping starts very early...etc...as soon as the transistor starts swinging the collector voltage in response to input, it starts running out of room to swing.
May sound 'pinched'...lol.
Very 'different' approach = different Fuzz Sound...cool !
Anyway, with such a small bias voltage, if anything 'moves' like say a transistor drifts or...the small opening of the window gets closed completely.
@@R@te That's my take on the design approach or result.
I'ts kind of a 'wierd' sound for a distorter, at first...seems too wierd...wierd tone can be cool once you adjust your pallete and acquire a taste for it, adding 'spices' to this dish...spices it up too. Slamming the input with more voltage via other Boost or Fuzz being one way to spice it up.
Can sound like an 'octave -the octave', gnarly Fuzz, nasty fuzz,
If it's real bad gatey and you'd like a little more signal to swing through...I'd mess with 'opening up' the bias a little or a little more..., as Gus and others have done.
Hey all, If any are still interested in this I finally got around to messing with my original Fuzzrite some more (delicately as possible)
But first , and this pertains to one of the last posts here. I got the "stompbox" book by Art Thompsom from my wife for Christmas (it was my second choice If I couldn't get Mike's book ; ) I was very pleased with it btw far as the historical front. And I was very surpised to read in the section on MOSRITE , a little quote from the founder / creator of the Fuzzrite that " Only the first 250 Fuzzrites were made with Germanium trannies, when i discovered that they wouldn't fuzz right (haha) when set on cold concrete", "we then switched to silcon transistors for production"
so as far as I take that at least, the one I own , being the Germanium equipped model , Is actually ONE of the original 250 made , and only ones to ship with the germ's in there!!! that would make it even more of a collectable. On to the issue I have with it , which makes my findings even more depressing as i think that tranny has problems
I did get around to pulling up the Collector lead on the Q2 since the Base was already disconnected I figured if I pulled the B and C I could leave the Emitter to ground and it wouldn't matter , then I could make a little "in circuit test jig " to solder in other PNP's and test the circuit around Q2.
Well first off I dropped in a 2907 sili pnp and right off the voltages become substantial !!! I got a vltg of 1.2v for Collector and apprx .550v for Base. So this alone prob tells me that the original 408germ is no longer good (with it's 70mv C and 55mv B) anyway I also noticed , and I didn't mention this before , that the squealing / oscillation that I sometimes would get when I switched On ,which was also controlled in pitch and volume by both pots, seemed to be gone. Now there is definitely still misbiased/gating with that tranny I dropped in but that's likely to be expected.
So IF it's now obvious that the Germ Q2 was bad , would the best way to go about it IF i wanted to replace it , to just leave 'test jig' wires there and try soldering in several different pnp Germaniums till I find one that biases out pretty well ? rather than just picking one and then worrying about the resistor values. and if so and looking at the schematic... a Higher gain or Lower gain for Q2? I assume not the hfe like a normal fuzz face?
THANKS AGAIN
Well another discovery! maybe the original q2 isn't bad?
While I was clipping in other trannies for Q2 I found that any Ge I put there was still getting those horribly low C/B readings ( 30mv-80mv range) with less than 10mv or so drop between them.
BUT it wasn't til I sort accidentaly struck the strings (fuzzing) while the probe was at the collector, that I realized I WAS getting a higher voltage there!! so I checked this way and where I got 70mv C and 60mv B while "idling" ... I was seeing around 3-4volts Collector and 1-2volts Base WHEN THE STRINGS WERE HIT!!! and yes, even with the original Ge in the circuit!
So , besides the posibility that the tranny wasn't bad , what does this tell us? Looking at the schematic I linked to, what could possibly be the cause (IF this isn't a normal occurance that is) of this ? and so far as I could tell Q1 doesn't do this , it reads proper vltg regardless. AND when I had a silicon rigged in there for Q2 it also seemed NOT to matter if the strings were struck or not. I got same 1 bias voltage regardless.
thanks
Well another discovery! maybe the original q2 isn't bad?
While I was clipping in other trannies for Q2 I found that any Ge I put there was still getting those horribly low C/B readings ( 30mv-80mv range) with less than 10mv or so drop between them.
BUT it wasn't til I sort accidentaly struck the strings (fuzzing) while the probe was at the collector, that I realized I WAS getting a higher voltage there!! so I checked this way and where I got 70mv C and 60mv B while "idling" ... I was seeing around 3-4volts Collector and 1-2volts Base WHEN THE STRINGS WERE HIT!!! and yes, even with the original Ge in the circuit!
Generally bias is taken with the transistor having no real input. I wondered if the bias voltage didn't rise on the collector when signal 'pushed' on the base.
So , besides the posibility that the tranny wasn't bad , what does this tell us? Looking at the schematic I linked to, what could possibly be the cause (IF this isn't a normal occurance that is) of this ? and so far as I could tell Q1 doesn't do this , it reads proper vltg regardless. AND when I had a silicon rigged in there for Q2 it also seemed NOT to matter if the strings were struck or not. I got same 1 bias voltage regardless.
I would guess everything might be close to 'right' with your circuit, this would mean that the voltage on Q2 collector rises with signal input to circuit.
Well thanks for your input on it. If this is normal operation than this is definitely something I've never seen before in a Fuzz crkt. Though yes It does make theoretical sense.
I really do need to whip up this crkt ASIDE from my vintage unit so I can check things out. but I just am a bit short on jacks etc.. right now ( I HATE Salvaging from other projects even if they're not being used as that usually means in my case that there's little chance they will be again : )
BUT I WOULD need to wire up the bypass switchign the same as it is on the stock unit (which is very unique if you recall , with Battery + and ground going to one outside lug and Q1/2 Emitters 'grnd tied to the middle two lugs ...Input/Output at the opposite side lugs. Anyway i will need to do it this way to see how it behaves I think. the switching may be what is causing some of my problem with the big dying animal screeching sound charging / discharging with the switchi!
I obviously just hate to try another switch in there , If I had an old Carling DPDT to put in I likely would though
Hey all !
I finally got around to tackling the misbiased Q2 in my Ge Fuzzrite clone built from Andy's vero layout. I did as Gus suggested and replaced R3(the 1M resistor between the Collector and base and threw in a 2.2M (pretty much all I could find). The old DC V readings were :
Q1
C=2.77v
B=0.1v
Q2
C=0.2v
B=0.08v
With the new resistor in place:
Q1
C=3.15v
B=0.1v
Q2
C=0.35v
B=0.08v
This mod has definately got my Q2 distorting nicely but I have no idea if this is optimal because there isn't much of a tonal difference between Q1 and Q2 right now. I also believe I have lost some output from the circuit. I'll have to install a pot and do some fine tweaking but I'm happy that I've improved the sound of the box. I have no idea if any of this will be of any help to Analog Kid or not. Thanks to Gus for the suggestions.
Chris