The Amp Garage

the diode D1 next to R2 looks like it might be there to introduce asymetrical clipping.....if its a silicon look into replacing it with a germanium
or fiddle with D1 and R2 ... or replace with a diode and or LED network to change clipping levels witout messin with the rest of the circuit....

I've often thought to try a modular line filter.... but havent yet
seem like they would make for a really cramped chassis...
maybe on the fil. voltage ... its the least regulated

check out Aiken Amplifications tech section.... the 70% rule is valid... I've seen that in more than one spot it keeps the valve from crossing the max watts limits when amp is really pushed..... and you really do have to do the math its not where you set the milliamps....it where you set dissapation...

observe the "design-maximum values" in your tube manuals I have a pair of 6L6 from the early 50's that still in very good shape but the new tubes dont seem to be the same caliber... a guitar amp is just about the most abusive use of a tube... I know full time giggin musicians who can still get 5 to ...

I think it was the other way round..... pull a pair and you had to double the spk imp to end up with the same effective impedance... with the cathode switch Id double check if the switch was break before make...or make before break..... if your in standby, there still might some voltage soak left in...

there was this trick to reduce the volume of a fender twin by pulling out half the tubes... a lot of players did this... without paying attention to the issue of effective impedance matching....without serious distortion and without serious detriment to the amp.... I've found good reffences that thi...

My favorites are jensen aluminium and oil..... what ever you choose keep in mind that the interior of an amp will get hotter than you think.... you can can also parallel caps of differnt types to augment the sound of the amp towards the tone your after...... the best caps for a black face are the ca...

after some more digging... there is a serious gap in the available information about transformers... we assemble... we dress the cicuit..... we design..... amps not the parts that we do all that with...the information about transformers we need to do that is as a matching device.....turns ration and...

The problem is the model that the math is based on... its a rule of thumb based on an "ideal transformer". It leaves out all of the real.. proper evaluation uses a open-circuit and short-circuit test as a "general practice" to provide data for an "approximate equivalent circuit" that gives accurate ...

I did some digging and found a much better explanation You've run into the "Primary Inductance" of the transformer. When a current is applied to a transformer, it induces a voltage that opposes the applied voltage, this is called "back emf". The magnitude of the back emf is dependant on the rate cur...

I have a McIntosh MC225 stereo on the bench
It needs replacement electrolytics in the power supply
In the voltage doubler...looks good other wise
these are cornell dubilier 150MFD 250WV
" UPE15025T" twist lock
I try to keep things original where possible
do any of you have a lead to source these?

I have a Gretch on my bench that has tone control you might like. Its a G-6162 and a schematic can be found under bargain bin at schematic heaven.... Dual twin reverb... on paper it looks weird... its a phase angle thing similar to the tone control used in a big muff.... its very useable for a one k...

Amen..... I had a pile of junk, a cheesey ohm meter, and a soldering iron.....the first chassis I beat out of an old heat sheild from the back of a wood stove...... I've used mixing bowls and scrounged street signs..... dont let yourself be convinced that you have to get this or that just because....

the current project is nearly identical to a 5C3..... and has 12AY7..... the 12AX7 has a more limited bandwidth but sounds phatter ...but the 12AY7 has the detail and sweetness... the next on the bench will be close to a 5D3 with 6SL7 thru out..... they'r great after warmup.... itll be good to A\B a...

Thats part of the attraction..... the simplicity.... the reason ,I guess, why its not favored is that theres a inherent distortion of the negative side of a sine wave being reproduced from the get go..... but that doesn't explain why it favors one type of pickup.... the amp is fantastic.... but only...