A Couple Of Patriot 2X12 Tech Questions

[frankie5fingers]

This is my first go-round with this amp and beyond an occasional review there isn't much info out there so a few questions for some of the more experienced if you wouldn't mind.

First, I can't find a schematic anywhere, does anybody know where to get one?

 

Next - there's a faint 60 cycle hum when powered on, not loud enough to notice except in a dead quiet situation. It doesn't get any louder and there's no other effect whatsoever. It's not an issue per se' but I'm wondering if it's the norm. It has Mercury Magnetics iron BTW (not sure if they all do).

 

Finally, anybody do any tube rolling - suggestions? Currently I have Sylvania 6L6s, Raytheon 12AX7s in V1, V2, a Mullard CV4024 in V3, a Sylvania 12AX7 in V4 and another CV4024 in the PI spot. With so many pre slots it could take a while to try every tube in every one so.... anybody have a better set-up?

 

Thanks.

[212Mavguy]

In the tube rolling department try RCA short plate 12ax7a/7025a or RCA short plate 7025 in V1. Although they look identical internally, they sound different, more gritty with the 12ax7a/7025 than the 7025. That provides vintage Fender tonal roots to build from. Look for a Siemens, Amperex, Philips, Miniwatt or Mullard short plate ecc83/12ax7 for V2, interaction with RCA is great for dirty tones with short plate Philips family 12ax7's. If you want to use that Raytheon in the V4 instead of the Sylvania, it's likely to be a bit less loud and warmer sounding if that spot is reverb recovery. There are lots of different construction in Raytheon 12ax7's, I can think of at least eight different US, German, Yugoslavian and Japanese builds with Raytheon 12ax7 labeling. Hard to beat the CV 4024 in a 12at7 PI spot. Those two CV4024 tubes can stay right where they are. Tough to beat their sound and durability.

 

Don't worry about that tiny bit of hum.

[frankie5fingers]

Thanks Mav. These are the Raytheon long black shiny ribbed plates, early '60s. I don't have any rca AX7As, I'll have to try a few. I was thinking I might try an i61 in V4 but what you say about the interplay between V1 and V2 sounds interesting - I'll look for the RCA and use an Amperex in V2. Thanks for the suggestions. Oh yeah, and no question the CV4024s are the right play - there's no other AT7 with that fatness and presence.

Thanks again.

[rjsanders]

what mav said + have you tried a variety of AC plugs & locations? the Pats i've played were in a music store with excellent line filtering, etc. & no 60cycle hum or noise.

[rjsanders]

& oh yeah: there are no schematics anywhere that i could find online + i keep forgetting to ask PaulC about 'em the few times we've talked...

[Gitfiddler]

My Patriot is quiet as a church mouse. Any hum is likely a bad tube. But from reading your posts, you know a bunch about good glass.

 

I wrote to Paul Cochrane and even spoke with him once about Heritage amps a couple of years ago. He is SO proud of those things. Rightfully so. He said that there were no published schematics done, but all of the amps are so straightforward, any qualified amp tech can suss them out..

[frankie5fingers]

Thanks Gents. I tried a few tubes (RCA on the way Mav) with no effect on the slight hum. It's so slight; I'm sure it's nothing mechanical - it's been pretty well cared for. Although I'll check lead dress, ground points and the like I'm sure it's just a little more sensitive to its location than its older brothers and sisters.

Too bad about the schem though...

Anyhow, thanks again for the replies.

[212Mavguy]

Let us know how things go and best to you!