Kara-Moon Forum

  ...Yes of course ! 8)
41 years I´ve been messing around with music and my first guitar was also my first victim of my first customizing attack, of and endless row...
In all that time lots of instruments and gear passed through my hands and ears.  At the end (of my life in Belgium) I had a second hand music shop and did a monthly second hand music market in Antwerp and Brussels.
A good guitar was no problem; I just make one, point. :lol:  :wink:
But the amps always missed something and my knowledge on electronics was/is too basic to create a good one myself.
Funny enough, the guy that inspired me to move over to Canarias was also a very handy electronics wizzard, with a fascination for music and had made his first guitar amp 45 years ago... :shock:
The rest of the story you can guess, except the end :
In the meanwhile I have got a few perfect and unique guitar amps, but my friend has died (in 2006).
He once told me never to show/share the electronics schemes while he was alive (long before he even got ill)...
He did an absolutely great job and could spare lots of time in research. 

When I met the guy I had already a clear view of what my ideal amp had to be and what not.
The amp had to be completely silent, ´cose I make the noise. :wink:  :hihi:
I mean : take any amp, without connecting anything on the input and open all volume and tone knobs.  When one uses a 4 speakers bin (1 pair of bass and a pair of guitar speakers cross-wise placed) you have to run away from the hisss and hummm the amp generates (imagine adding the noise of the other amps of the band, in that typical small rehearsal room, multipied by those many years).

Using resistants and condensors of high quality (10x more expensive, but not important in the total cost) elliminates that, together with the tubes, instead of transitors (another fountain of noise).

The amp had to have a powerfull warm sound, so it had to be type A, like a Vox AC30.  AB amps give more watts, but a "cold" sound...
My friend changed also all of my other AB amps (Fender, Marshall, etc... ) into A amps and the result spoke for itself.
A year ago I´ve sold 3 of them to some young kids and they couldn´t believe their ears; I´ve never seen people being so happy ! :D
The Vox AC30 was the reference I gave to Walter, ´cose that was the amp I prefered.

I make my sound with my fx´s, so a simple (bass-treble) EQ is all I need, but I kept the simple high-cut (1 condersor and 1 potmeter on the output in the power amp) of the Vox.  This way I can boost highs and cut off the sharp 'points'. 8)
IMO more efficient than a flexible mid.
Now it has 2 different pair of tubes : two 6L6GC for the warm sound and the first 30 watts, then 2 EL34 for an extra hi-mid with the last 30 watts.
30W more isn´t that much more for the ears ! (volume isn´t liniar)  IMO a 2x12W is more efficient and less weight to carry !
2 main inputs : a normal (à la Vox) and a 'brilliant' one with a special designed preamp.

A simple, but perfect amp : it just amps my sound as I want it !

The price can be cheap if you´re able to find an old broken tube amp.  The 2 transfo´s must be OK though, that´s the most expensive ! Sand, paint the chassis, redo the wooden exterior and the front plate.

Having the opportunity to elaborate my ideal amp in these conditions was in fact like a dream !

The schematics and warm greetings,

Max... .. . :;

PS : I´ve made photos of the amp; due to being very tired, I made the error taking only 1-shots, resulting in 3 badly focussed and 1 clear photo (the most important 8) :-).  On the inside-top you can even see that a mouse is using it as a W.C. ! ::)

Thanks for sharing. I'm always interested in valve (tube) designs as these were what I cut my teeth on :)

A very common trick was to put a pot in anode of the 2nd output of the phase splitter (rightmost tride in your drawing) so that, with the aid if a 'scope, the drive to the output valves could be balanced.

Another trick was to have the standby switch only cut the feed to the screen grids of the output valves, as power valves don't like being left for long periods with heaters on but no anode current at all.

I don't think I'm good enough into electronics DIY stuff
but I save these schematics just in case...

Thanks for sharing the secret Max  8)

Cheers

Folderol, thanks for the extra info.
I just lended my ears and ideas to the project.
IMO, these things have to be shared as much as possible. 
A good instrument and getting the sound you want inspires and animates more of course.

Cheers,

Max... .. . :;

PS : Laguna Rising, a good idea, in case you find a friend that can help you out and now you also know why you may not throw away old tube amps... ;)

Very generous of you, Max!

I don't use an amp, but this sounds tempting... ;D

Too cool!  Like LR, its way over my head (probably farther over mine than LR's  :D). Would love to have one though. I'll keep the schematic. Maybe I can find someone to build one for me.

ps: maybe not. Can't get it to download.

For years, no, decades, I've been saying to myself that I'll build the ultimate amp ...

... <sigh>

BTW anyone who works on a valve power amp, watch out! There are some very nasty voltages with lots of OOMPHF behind them, and high voltage DC is far more dangerous than AC.

120V AC - you call a doctor
240V AC - your friend calls a doctor
415V AC - your family calls an undertaker
750V DC - the police call the fire brigade

P.S.
A pair of KT88s can have their anodes @ 800V and EL34s @ 825V
Anode-anode swing can be up to 2kV :o

Tx folderol !
"If you´re not handsome or strong, you have to be clever", used to say my uncle Frank. ;)
If we´d be electronics wizzards, we all would have had our best amp in the world, already !
I didn´t made mine either.   8) Just keep the plan and start looking for an old rotten tube amp and a friend that has the know-how.

Recycling and collaboration ! Togetherness ! Djee, a little more and we start throwing flowers to each other; spring is in the air...

Cheers and a good night,

Max... .. . :;

Hi mates,
 
I´ve made some photo´s of in- and outsides of the amp; showing it´s clear simplicity !
I´ve put them next to the scheme, at the top of the thread.

Cheers,

Max... .. . :;

Priceless, Max.  I mean it! Here's some flowers for ya... :-

(photos and drawing go in a folder for a future build :-*)

Whoever built that amp actually knew what he was doing ;D

It is a very pleasant change to see neat correctly dressed wiring and clean smooth soldering!

Forderol you got it right ! That guy was realy fantastic in everything ! For him, problems existed to get their solution. 8)
Some people you miss a lot more when they fall away...
He always spent the 6 cold months here with his wife in his "mobil-home-truck" between the locals and used to fix their broken stuff.
Anecdote : a guy stepping down from the buss sees a good looking TV set, next to the garbage container.  Takes it to Walter´s mobile HQ; he fixed it and the bloke went on to his family with a brand new free TV !

Sharing one of his 'piece de resistance' was something I owed him.  The wonderful reactions of all of you would have put that typical foxy smile on his face.
Thanks ! ;D :-*

Cheers,

Max... .. . :;

..hehe..and if you aren't going to be smart, you'd better be tough.

 :D

Wyatt

 ;D lol