Re-modded my Picovalve

[wagdog]

Pretty extensive makeover for this little amp. After the first go-round, I was sort of disappointed with it. In this round, I took the board out, cut traces and rerouted things so there is a recovery stage after the tone stack. In the process I lost the cathode follower prior to the tonestack, but it's worth it.

That and a few filter/circuit changes and this is a fire breathing monster of an amp. It is LOUD - I gigged it this past weekend and it easily kept up with the band.

Video:


Schematic and description: http://wagner-usa.net/picovalvemods/

 

[Modern Saint]

Sounds cool Wagdog!

I haven't done much with mine since I got it. Bought a 5881 to replace but now I am intrigued about the 6550.

 

[telecaster911]

Is that the 6550? Sounds cool

 

[Chad]

Sounds good.

 

[wagdog]

Sounds cool Wagdog!

I haven't done much with mine since I got it. Bought a 5881 to replace but now I am intrigued about the 6550.

Thanks man! This was a bit of work figuring what traces to cut to move things around, but once I started rolling it wasn't that bad. I couldn't get a decent feel/tone out of it without going this route. Fwiw, if you ever decide you want to get rid of yours, I'd be interested in picking up another. There are some things I want to try, but I'm done messing with this one, it's a keeper.

This amp is super touch responsive, it just feels alive.

Is that the 6550? Sounds cool

It is, and thank you again for sending it! I've tried it with a: 6v6, 6L6, and an el34. That 6550 has the headroom I'm after. The other tubes sound ok until it gets loud, then they just sound splatty.

 

[Modern Saint]

Thanks man! This was a bit of work figuring what traces to cut to move things around, but once I started rolling it wasn't that bad. I couldn't get a decent feel/tone out of it without going this route. Fwiw, if you ever decide you want to get rid of yours, I'd be interested in picking up another. There are some things I want to try, but I'm done messing with this one, it's a keeper.

This amp is super touch responsive, it just feels alive.

Not planning on flipping. I bought so dirt cheap ($99) that I had some plans to mod yet just may want to use it for recording or teaching. Just haven't played through it for a year plus. Irony is that it is still in the box that it was delivered in.

 

[wagdog]

Not planning on flipping. I bought so dirt cheap ($99) that I had some plans to mod yet just may want to use it for recording or teaching. Just haven't played through it for a year plus. Irony is that it is still in the box that it was delivered in.

No worries. If you ever find you need to fund some gear, you know where to sell that one quick.

I should have bought a few when they went for $99.

 

[wagdog]

For anyone who follows these mods... I tried reconfiguring the triode before the tone stack as a cathode follower tonight (staying more true to the Marshall design) - it really didn't sound as good, so I went back to my v2 setup. I also changed the last coupling cap (C6) to a .01uf as opposed to the stock .022uf. It took a little bit of the bass out, but in doing so, the lower strings sound clearer (sometimes taking some bass out will do that).

 

[xStonr]

Sounds good. I picked up a Picovalve when MF had them as a SDOTD. Out of the box it sounded like a blanket was thrown over it. Since I don't have the skills to work on an amp's innerds, it went back. Congrats to you on your perseverance with the amp.

 

[wagdog]

Sounds good. I picked up a Picovalve when MF had them as a SDOTD. Out of the box it sounded like a blanket was thrown over it. Since I don't have the skills to work on an amp's innerds, it went back. Congrats to you on your perseverance with the amp.

Wish you still had it, I'd like to pickup another one.

Yeah, I couldn't get past the blanket over it feel to the amp. I've done some pretty severe mods to the circuit board at this point. I've modded it even further since posting this - the clear tone is really nice and the overdrive is a bit smoother.