The Amp Garage

Looking at a Traynor YCV40. http://i131.photobucket.com/albums/p315/naazrael/TraynorYCV40.gif vectorized form - schematic starts at Page 8. http://www.traynoramps.com/downloads/servman/smycv40.pdf I was thinking about modding mine a bit, just for kicks. The first tube stage kinda looks like a Vox, i...

Firestorm: I just started modding amps, so I'm not all that familiar with every bit of tube amp circuitry. It just seemed that I didn't have much voltage stored up, as measuring the caps didn't show significant charges. I still drained them with a clip + 100K resistor grounded to the chassis, of cou...

Okay, cool. I was planning using a Hammond JCM800 choke, fwiw, since the VTM is a JCM800 copy. That quote was taken from a thread where someone added a choke to a Peavey Windsor. He also upgraded the output transformer. He reported a noticeable improvement in tone, so I wanted to see what other modd...

here's what was said in another forum about adding a choke: I once asked Peavey why they did not use a choke in their tube amplifiers - the reply was that it was cheaper to use a high wattage resistor and maximized their profit margin. Sad really, because the choke plays a MAJOR influence in the cla...

Here ya go:
http://www.netmusicians.org/index.php?s ... value=6160

I brought it to band practice, sounded great!

I did both cap mods, the 330pF and the .68uF ones, as I felt it needed to be thicker. The amp feels really articulate and responsive now.

I did a quick clip at band practice, I'll upload it later.

Here's a quick clip I did:
http://www.netmusicians.org/index.php?s ... lue=azrael

The first part is with the volume rolled down, to show that it still cleans up nicely.
Then some rhythm, and some lead. I apologize for the rubbish playing!

Actually, FWIW, every gear on the Splawn had very usable tones and was also relatively low noise, for the amount of gain it had. :D and while I know you put up your disclaimer of not being an expert, your experience with the JCM800 circuit and it's modifications has been invaluable. I think I now ha...

Awesome, I'm really glad I posted here. A lot more help than I've recieved at other places. Thank you. :D Okay, let's see if I can attack your post bit by bit... That's very interesting about the different styles. Should I change that resistor back down to 100K? No problem about volume. i crank this...

Back when modding Valve Juniors was the hot ticket, I remember reading an article where one guy had a bulb as an attenuator, I think.

R2 on the preamp board is the anode resistor aka plate load resistor. If you consult a Load Line drawing for a 12AX7, the typical bias point for most classic amps is 100k for the plate load resistor and R1 and R2 in most Marshalls and many, many other amps is 100k. This is very typical for most amp...

And for the record, while I wanted it spud more like a JCM800, I'm also trying to get "that" sound. I want a beefier and fuller JCM800 tone. One amp I can think of is the Splawn QuickRod's second gear. That is an awesome OD tone. I had one more question: any more ideas on how to reduce the hum/noise...

Hey dude, wow, good price! You can't go wrong for that. thanks! it was totally worth it! I'm not sure what your goals are for the amp tonewise... are you trying to make the amp more JCM800-like or go in a different direction? Already, your amp should be a gain machine and while it shares some DNA w...

I took the plunge, added the bias mod, went with the Super Lead style 68K resistor in place of the treble peaking circuit, and I also changed the slope resistor in the tonestack to shift the range and make it more meaty. It's running at about 28mA, I may try and get it hotter. Definitely pleased wit...

Hey guys, a little while ago I was looking to build a JCM800, or buy one for cheap. Instead, I ended up finding a Peavey VTM60, one of Peavey's own "JCM800 killers", for really cheap. Got the fullstack for 300, plus a PA head. Couldn't pass it up. Anyway, the amp sounds great, just needs a bit of fi...