Help trouble shooting new Rocket? (pics added)

[passfan]

The resistor to ground off the center lug of your bass pot isn't coming into contact with the pot before it gets to the resistor, is it ?

[CapnCrunch]

The resistor to ground off the center lug of your bass pot isn't coming into contact with the pot before it gets to the resistor, is it ?

I am going out to the shop to check all the wiring and all the connections this morining. I do know that the resistor is not contacting the pot. I checked that one last night.

Thanks to everyone for looking and the ideas. I'm sorry that my pictures aren't clearer.

[CapnCrunch]

UPDATE:

Well after going over the entire circuit with the layout in hand and a bright light I discovered that I had the wrong bias resistor for V1 (R5 on the layout)
installed. Instead of 1k5 I had a 68k resistor in there

Long story short, I popped in a 1k5 and touched up every solder joint. I plugged in my LP and now I know why folks rave about this amp. I have a few other issues with my pots that are confusing to me, but the amp sounds awesome. Great clean tones and great OD tone. With the amp volume 3/4 up and guitar volume on 10 the notes sustain indefinitely.

Thank you everyone who helped me figure this out!!!!

[M Fowler]

Glad you found the main problem.

The pots could be bad not the first time and I recently had some PEC that I wasn't very trilled with so hence the reason I went to CTS from mojo.

Mark

[passfan]

Glad you found the main problem.

The pots could be bad not the first time and I recently had some PEC that I wasn't very trilled with so hence the reason I went to CTS from mojo.

Mark

I'm starting to run into some of that as well. I've got a couple that have some funny spots in them. I guess I'll give the CTS a shot. You couldn't find them any cheaper than Mojo's ?

[rooster]

Hmm, when you say, Mark and passfan, that you are having problems with your pots -- this is refering to the PEC pots? Have you pulled the backs off of them and cleaned them thoroughly?

Mark - are you saying you find the CTS Mojo pots better than the PEC pots??? Are these different than other CTS pots you can buy? IS the Mojotone version special??

[M Fowler]

I doubt if the CTS are better than the PEC or Clarostats. No claim that one is better than others.


I got some new PECs that show problems as you turn the wiper and no I did not clean the pots yet, I will do that.

I just started using the CTS from Mojo as well as the CTS that mojo has made for them. So far I like them. The problem for some people is the stiffer feel that these CTS and the Bourns pots have, but I like mine that way.


Mark

[Structo]

From what I have read, CTS can build the pots to any specification you want.

They can make them tighter or looser on the bushing and custom tapers as well.
You can specify no grease for lube or even the shaft or bushing length.

Now, I don't know how many you have to order, probably 1,000 pcs. but I do know that I have bought 250K CTS guitar pots that really vary in the way they feel.
I have a couple on my P90 Telecaster that have a lot of slop in the shaft and bushing and if you blow on them they will rotate. (well not really but they turn super easy).

I have a strat with CTS pots from a different vendor and they are very tight feeling.
I don't like a guitar too tight on the pots but I also don't care for a lot of play in the bushing clearance either.

So somewhere between those two is the perfect pot for me.

The PEC pots I have bought from a local vendor have a medium turning resistance that feels good and high quality.
Plus they are sealed which may be a good or not so good thing because the only way to clean them would be to take the can off and I have had the little tabs break off before when bending them.

[M Fowler]

I'm looking for some good pots for my Gibson The Paul I put in 500k Bourns but when you get to 9-10 it reduces the volume.

Any suggestions. I have PIO caps already.

[passfan]

Hmm, when you say, Mark and passfan, that you are having problems with your pots -- this is refering to the PEC pots? Have you pulled the backs off of them and cleaned them thoroughly?

Mark - are you saying you find the CTS Mojo pots better than the PEC pots??? Are these different than other CTS pots you can buy? IS the Mojotone version special??

Well they hardly have any time on them. Do they still need cleaning ? Is this something you do with new ones, and what do you use to clean them?

[CapnCrunch]

The PEC pots in this amp are new. This is the my take on them. The volume, bass, and treble pots are all scratchy, and the bass and treble pots have dead spots near the end of their sweep. They look cool, but I'm not at all impressed by their "quality".

I'm getting used to the interaction between the tone pots. They act like gain controls. I spent about an hour with the amp and my old Tele. WOW. Unbelievable clean tone. Like the best Fender clean only not brittle. It's just alive, and the notes hold on forever at low volumes. Absolutely no need for reverb, but it would probably be cool if you had it. Very, very cool amp. I turned the volume to 12 o'clock with the Tele, which is quite loud, but not a hint of hair unless I absolutely slammed the strings, then I'd get a little. I was so mesmerized by the cleans that I never even cranked it up to see how it would sound wide open with the Tele bridge. Played it through a 65 amps 2x12 with alnico gold and g12h30, and through a 1960a with greenbacks. Different amp depending on the cab, but they both are great for this amp.........

I'm a happy man right now.

[Structo]

I'm looking for some good pots for my Gibson The Paul I put in 500k Bourns but when you get to 9-10 it reduces the volume.

Any suggestions. I have PIO caps already.

Mark, this may or may not be the answer you are looking for but I remember years ago a guy told me something about guitar pots.

Most of the time the ground point is soldered to the back of pots.

But with the PEC pots we know they are stainless steel so they don't solder easily, without sanding and perhaps flux.

The thing this guy told me is on guitar pots when we solder on the back, is to turn the pot CCW all the way to zero before soldering.
He said the heat from the iron can screw up the trace and create a dead spot so if you have it on zero there is less risk of having a dead spot on the important parts of the trace where the wiper rides.

So I have always done that when soldering a new pot into a circuit, particularly if I am soldering ground wires to the back of the pot.

Now on PEC pots, don't they have a conductive plastic trace? Verses the more common carbon type trace on other pots?

So it could be heat that is damaging the pot.

[M Fowler]

That could be the problem Tom I'll replace the Bourns guitar pot with a CTS 500K and see what happens.

Sorry to have derailed the thread somewhat guys, you too Jana.

Mark

[rawnster]

Hey CapnCrunch, nice build. Looks clean. I like the heater colors. It's nice to read your response on how clean the amp's tone is too. It is a clean amp; and yet be driven to nice crunch and grind. Have you tried any overdrive pedals with it?

[M Fowler]

CapnCrunch,

I added a switched 10uf cap on the bias of V1b that adds some nice gain.