frequencycentral "OBSESSION" Guitar Amplifier

[starekase502]

ok, ok ill be "that guy"
any plans on releasing the build details to the rest of us.

[solderman]

Rick
You have out done your self again.
Excellent job.

Silly question, how did you get the tubes to glow blue?? The obvious would be a LED but the tube socket is not transparent, at least not the one I have seen??

Sound samples pleas 

[Scruffie]

Rick
You have out done your self again.
Excellent job.

Silly question, how did you get the tubes to glow blue?? The obvious would be a LED but the tube socket is not transparent, at least not the one I have seen??

Sound samples pleas 

I think from the look of the pictures, you can see a resistor on the pins of the Tube Socket and I think it's leading to an LED in a hole in the center of the socket, my guess atleast.

[elshiftos]

Work of art!

Couldn't agree more - it's amazing!

BTW, this fellow Surrey-ite LOL'ed at your avatar

[elshiftos]

ok, ok ill be "that guy"
any plans on releasing the build details to the rest of us.

+1
I've got some 12AU/12AX and a 2291 requiring a home!

[Thomeeque]

My new amp. Single ended, 12AX7 / 12AU7. Internal MAX1771 SMPS generating 240 volts from a 12 volt DC power pack. My best amp design so far I feel.........

Really nice, but I would not like to be asked to replace scratchy pot or dead component inside

[frequencycentral]

how many Db can this thing kick out rick?

Haven't measured for Db yet.

is it giggable as back line in your average pub when mic'd up through a P.A?

Probably!

Rick, I was just thinking, how does it perform hum-wise? I'm guessing the heaters run direct from the dc input, is that noisy? Also I guess that the heater feeds are short enough to not be to susceptible to RF, and are probably fairly well shielded by the chassis, but can you pick up any chopping noise from the switcher?

This has had a loooooong development period. No flaws.

Also, where did you hide the spring reverb?

You missed it? Look again. 

You need to start marketing these better: they're absolutely beautiful and people pay absolutely silly money for things like a zvex nano.

Yeah, working on a website right now.

ok, ok ill be "that guy"
any plans on releasing the build details to the rest of us.

Usually I share everything but this one dies with me. Sorry. I think it's HOT. Besides, when you know the four main components already, the rest just falls into place. 

Rick
You have out done your self again.
Excellent job.

Silly question, how did you get the tubes to glow blue?? The obvious would be a LED but the tube socket is not transparent, at least not the one I have seen??

Sound samples pleas 

I think from the look of the pictures, you can see a resistor on the pins of the Tube Socket and I think it's leading to an LED in a hole in the center of the socket, my guess atleast.

Yup! The tube sockets have a hole just big enough for a 3mm LED, this and the resistor are soldered between pins 4 and 5 of the tube socket.

Really nice, but I would not like to be asked to replace scratchy pot or dead component inside

Yeah, not fun. You have to know it's bulletproof before putting it together. I'm considering more easily servicable alternatives.

[Ice-9]

Hi Rick,

That is just the beautiful, I see you must of managed to get the Max1771 to perform well. Any sound clips available yet to have a listen to ?
Hey i recognise those valve protectors, same as the ones i use. There quite expensive but look really nice.
Congrats and when you get the webpage done don't forget to let us know where it is.

[Ice-9]

Hey Rick
Iv'e just had a thought, as this is a high voltage amp (240v) if you haven't already it may be an idea to use pin 4 of the MAX1771 conected to a microswitch, wich will dissable the high voltage circuit if the enclosure bottom is removed. If you are planning on selling these on your website, then it would help stop any numpties getting a 240 volt belt when they take off the bottom and poke a finger inside. Just an idea.

[dimi3]

Another great amp its neverending, btw did you maybee try ECC99 for output tube? I did this for my firefly build and it was like day and night compared to 12AU7, just a tought.

[gena_p1]

Brilliant work!
And You are the first, who did tube head in 1590B with full sized tubes!

I see no heat sink for IRF (IFR740?), looks worry.

This project must be commercially successful and popular with sofa guitarists!

[frequencycentral]

Hey Rick
Iv'e just had a thought, as this is a high voltage amp (240v) if you haven't already it may be an idea to use pin 4 of the MAX1771 conected to a microswitch, wich will dissable the high voltage circuit if the enclosure bottom is removed. If you are planning on selling these on your website, then it would help stop any numpties getting a 240 volt belt when they take off the bottom and poke a finger inside. Just an idea.

That's a great idea Mick, I'll look into that. Hey, thanks for the heads up on the valve protectors all those months ago too.

Brilliant work!
And You are the first, who did tube head in 1590B with full sized tubes!

I see no heat sink for IRF (IFR740?), looks worry.

This project must be commercially successful and popular with sofa guitarists!

Yes I am the first (beams!)! The IRF840 doesn't get too hot in this SMPS design.

[solderman]

Sound clips .....pleas 

[stringsthings]

most excellent 

[MikeH]

ok, ok ill be "that guy"
any plans on releasing the build details to the rest of us.

Usually I share everything but this one dies with me. Sorry. I think it's HOT. Besides, when you know the four main components already, the rest just falls into place.  

Just don't ask us to debug it for you and we'll be cool with that.  

The 12au7 does suggest a firefly-esque output section... The tranny is a 125a sort of thing I assume?  

Looks absolutely awesome as always, Rick.  I hate you so much.  

[Slade]

Sound clips .....pleas 

+1
Still waiting for that...

[JKowalski]

Yeah, not fun. You have to know it's bulletproof before putting it together. I'm considering more easily servicable alternatives.

They sell PCB mount tube sockets of the same format as the ones you used, perhaps the board could be mounted to those, with a header connector to a board for the pots & a header connector that goes to all the jacks/transformer. Then you could remove the whole main board just by unscrewing the tube sockets and disconnecting two headers. If a pot is scratchy you could switch out the "pot board" with a new one and troubleshoot the old pot board later.

It probably wouldn't cost much more, headers+pins are cheap and the tube sockets should be about the same price as the ones you have. You can get the two PCB's made pretty cheaply too.

[Pigyboy]

Hi Rick,
Great build. Question about the power supply if I may. I was wondering the difference between this one and the other nixie supply that uses a 555 instead of the MAX1771. From what I can see on your board it is a very similar to 555 design with the IRF740 and the inductor. I found this
http://www.allspectrum.com/store/product_info.php?products_id=521
Which looks to be the design of the PS you are using, yes? Do you find this one works better than the 555 circuit? Do you have the schematic for just the PS?

I found this too
http://www.tubeclockdb.com/nixie-kits/56-simple-nixie-power-supply.html
That supplies 180V from two 9V batteries.
Your amps are mobile Bro!
I wonder how long two batteries would last?
It would be cool if you could rig the battery pack with re-chargables and then you could have two packs and recharge one while you are using the other. The amp is so cool and so mini it would be killer to have the portable option!

[Boogdish]

My hat goes off to you, sir.  Can't wait to hear it.

[Scruffie]

Whatever happened to the Soundclips of this, You holding out on us Rick?