Hello and thanks

[gait]

Hello everybody, first let me introduce myself. my name is Gait en I'm 46.
I've been tinkering with electronics most of my life and I've been lurking
around this great forum for about 2 years.
Let me say thank you for everything I've learned from reading the posts
on this forum.

About 2 years ago I built my first tubeamp: a single ended Plexi on a
VJr chassis. After that a fullsize Plexi and a 2xEL84 Liverpool, again on
a VJr chassis.

About 3 months ago I decided to take the plunge and build a fullsize
Express. Mostly with second hand parts and transformers from an old PA.
The only things I bought new were resistors, capacitors, pots and knobs.

Because I used old parts I had to make different layouts for the electronics.
of the powersupply and the wiring. I had one Siemens EL34 and one AEG.
The preamp valves I used are Philips and Valvo.

To my surprise the amp worked well from the first go, the EL34 biased
at 42 and 44 mA and there were no oscillations, just a very slight hum
with everything flat out and of course some noise from the first preamp
stage.

And the sound is something to die for! I have heard sounds from my
guitars I've never heard before!

But, being the tinkerer that I am, I didn't stop there. I read that the
tuning of the amp is mostly done with the 2n2 and the 150k.
So I connected the grid of the 3rd stage to a jack chassis.
First thing I did was connect a 500k log pot which is then parallel with
the 150k. I was able to go from Fender clean to mucho overdrive with
a turn of that pot. Put the pot and a footswitch in a metal box and voila:
2 footswitchable sounds.

The advantage of a pot in this spot is that you loose the noise as well
as the overdrive at the same time. If you put a second pot with a
capacitor parallel with this pot you even have tonecontrol for the clean sounds.

But I didn't stop there. I took the first part of a runoffgroove EA-tremolo,
married the LED with an LDR and got an Express with footswitchable tremolo and clean sounds.
I have to experiment a bit more to make the tremolo sound better than
it does now but I'm definitely on the right track.

Ok, that's it for now. Thanks for reading this post and please do comment
on my findings.

Gait


d

[Gibsonman63]

Impressive and welcome. These guys helped my build my Express clone and now the rest of my amps are collecting dust... mostly.

Pics?
Schematic?
Sound clips?

[Richie]

But, being the tinkerer that I am, I didn't stop there. I read that the
tuning of the amp is mostly done with the 2n2 and the 150k.
So I connected the grid of the 3rd stage to a jack chassis.
First thing I did was connect a 500k log pot which is then parallel with
the 150k. I was able to go from Fender clean to mucho overdrive with
a turn of that pot. Put the pot and a footswitch in a metal box and voila:
2 footswitchable sounds.

Sometimes when you use things you have laying around,on hand,turns out very nice amps. You just never know till you get to play it.

That is one spot,and their are others.
It is nice to use a resistor and a small trim pot,and dial in or tweak while playing, to get what someone likes.
And even a switch to change cap values for that section. That way you could hear all the combinations of values.

[dynaman]

Scavenging for DIY. Love it! Pics?