The Amp Garage

Thanks for your answer. But what I mean is that in the calculator it seems like there is two different log/audio tapers (log type A and log type B) PLUS the linear one.

Hello everyone. I came acrosse the duncan tonestack calculator and noticed that there is two different log type pots (log A and log B). I checked, for example, the alpha pots specs and they mention only one type of log pot ... so, what is the difference ? What is the "standard" log type ? Are alpha ...

Great ! Thanks for your answers. I did noticed that there si not fancy tap on the PT secondary looking at the schem. But yes, there is a a relay for switching for drive/clean, it seems like it is powered by the 6.3vac heater winding. For the output transformer, I found some differences in primary im...

Hi, I'm on the path of building a silver jubilee 50w 2550 clone. I found some good layouts and shcematics ... but I just want to be sure to choose the right transformers. From what I found, I would need a 3.4K or 3.2K primary OT, a 690VCT (at about 200mA ?) PT and a 5H 120 mA choke ... can someone c...

According to the calculator on this website (https://thesubjectmatter.com/calcptcurrent.html), the amp should draw about 433.77mA with a 350-0-350 transformer, 4 6l6 and 4 12ax7 ... at 400mA rating for the edcor it is theoretically not enough ... maybe this could cause unwanted voltage sag when the ...

Great, thanks ! In fact, I think that what I want is more of that sax type smooth tone ... so High plate.

ok ... found these Edcore transformers that could do the job ...

power : https://www.edcorusa.com/xpwr173 (there is no 60V bias tap ... only 100v winding. Maybe some modifications to the bias circuit could do)

Output : https://www.edcorusa.com/cxpp100-22k

I'm on the path of building another ODS amp. I already built a 124. I'm going into high plate territory for sure. That being said, I'm pretty interested by the ceriatone OTS circuit (pretty much high plate skyliner with some twists ?). But the power amp looks different from, let's say, the 102 or th...

Thank you for your responses ! Very helpfull ... my ODS experience is pretty much low plate skyliner set up so I might go with high plate to compare. Maybe I would build some independent circuit blocks on a bench and try different tonestacks for example. And yes, I know it is very subjective. To be ...

Hi, I'm planning to build another ODS amp. I hope some of you guys would share some of your experience with diffrent ODS circuits. I just don't have the money to test them all and chose ... I already build a #124 circuit with small mods. I like it so far, but I realized the importance of the dumblea...

I built a 124 low plate classic and it is working just fine. I already did some modifications to it but I'm starting to dig some mods that requires to swap parts on the board. But how do you people do that without loosing the wires that are connecting from the bottom of the board ? For example, the ...

That's I was thinking. Thanks for the confirmation. I spent the last day playing with it and adjusting all the trimmers inside. Damn it sounds and feels great. I was craving ODS type of amp for almost 10 years, collecting information, listening to clips, analysing schematics. Now I can say that it i...

Thanks for your replies guys. I guess I just don't have much experience with these types of design. There is no filament center tap on 290fx from what I see on the spec sheet ... the only thing that could look like it is the two 120R that goes to ground from the 124 schem. But those have to be groun...

P/N for PT is 290FX. I can hold my fingers on it a maybe 6-7 seconds. The base (plastic part) of power tubes it is another story tough ... 1 or 2 seconds. My references may not be really good for this because my other amp has same transformer sizes but 50W power output (THD flexi 50) ... so nothing ...

I just fihished my ODS100 #124 build, and I have to say thank you to you all.I couldn't have been able to do this without all that information on this forum. I took the CE chassis, jborder boards (I have them since 6 years ... and hammond transformers). That being said, I have a question ... what is...