The Amp Garage

What is recommended for the bypass caps in the preamp? I was looking for philips bc, but then I ran into 030, 021 different two letter combinations lik EN, K8, etc. are all of these the same thing?

What are the best options for bypass caps here? I know philips BC KO are what seem to be in the photos - how essential are those?

Got it. Well, it wouldn't hurt to save the money on labor and resell the OT. I have a month before the tech can get it on the bench, so I have a little time to decide.

You think? I had heard these old seasoned Fender OTs are the best for these style circuits? I found a reputable local tech (Yontz @ Mad Science Raleigh) that can do the mod for me next month. I'm also trying to inch the Crystal over to as much of JM sig specs as possible - which from what I understa...

Yeah...it looks like a custom order from Marvel. It’s huge too. At least 25% larger than the twin!

No go. The Twin OT would have to be mounted 90s from what it should be and I’m not set up (nor really desire) to drill a chassis. Oh well...disappointing.

Good tip. I usually have the dog hanging out with me too. I’ll clear her out!

This all came about because another Crystal owner had Bill K swap a 70’s twin OT’s into his (along with a slew of other NOS mods) and he Couldn’t believe how good it sounded when he got it back. I’ve About maxed out the board for NOS components, so I figured I’d to the OT as well (not worried about ...

Well that’s encouraging. I didn’t really want to have to buy two new 8ohm 12-65s.

Yes, 12k and 8ohm tap.

Dawning I’m me that my 1X12 will be rendered useless. Don’t know many 100W 4ohm speakers. lol.

So I have this great Two Rock Crystal (basically the JM circuit) that’s been built with NOS components. I’m going to swap the Classic Tone OT with a 1970 Twin Reverb OT. Since it’s 4ohm, I know I’ll be moving the NFB tap and lowering the resitor to 8.2k (for a starting point). Any other modification...

Sorry, Two Rock Crystal. Essentially the JM circuit

Hey guys, pretty new here - so forgive me if this isn’t the proper venue for such a question. I have a crystal with some NOS components. Opened it up a while back and saw the cap tied to the master volume was .0015 instead of .022 like both on the board and on every JM layout out there. What effect ...