Help! Groove Tubes 12ax7s in a Rivera M60

I recently shifted the V1 and V2 pre-amp tubes in a Rivera Fandango from the 12ax7M's to the new JJ ECC803S's. *Much* airier and more open than the 12ax7M's. Very nice tone so far. I got them from Doug's Tubes. I think they cost $12 each or so.

As for checking for bad pre-amp tubes, you can try tapping each one with a chopstick lightly while the amp is fired up at low volume. If you get some strange noises, then the tube could be bad.

If that doesn't work, try replacing them one-by-one with known good tubes and see if there is any improvement. Don't replace them all at once.

 

Rivera pre-amp tube issues have been thoroughly discussed on this forum already.
The "search" function might come in handy.

This being said, as an M60 owner, I have figured out that the best preamp tubes to use seem to be chinese tubes.
It seems NOS are not the best choice including Mullards.
Golden Dragon tubes do wonder in those amps.
Rivera amps seem to be dark-ish amps, they match well with bright tubes.

However, I do use a 12AX7GT Mullard RI in V2, which helps channel 1 a lot in obtaining that classic Marshall grind.

YMMV.

 

This is a great Rivera website. They have some great advice on preamp tubes. I have used the budget preamp tube guide and had great results.

http://home.bellsouth.net/p/s/community.dll?ep=16&groupid=218298&ck=

 

Getting really dark can happen with some types of preamp tubes in Riveras. Groove tubes in all positions can do this. Try sticking a Chinese 12AX7 in a place or two.

Here is a link to some more info:

http://bellsouthpwp.net/r/i/ricjohns/Rivera Preamp Tube Guide.htm

 

It strikes me odd that you want an "airier" sound than the M's....i find them to be the airiest 12ax7 i have ever used by a mile. But then again now that i think of it, they didn't sound all that airy or even necassarily very good in another amp i tried them in. Guess they're very amp dependant. But in my C30 they are incredibly airy, or maybe a better description yet would be "transparent".

 

I own an M60 and have read all the web based advice. Here's what I ended up using as the best balance between the fender and marshall sides of this amp:

v1=EH12ax7
v2=Brimar cv4004
v3=chinese r9
v4=chinese r9
v5=sovtek 12ax7LPS

This is just bright enough to make the fender side chime and dark enough to make the marshall side distort without raspy high end.

BTW, this is one great amp, built to last.

 

Greggy,

here is mine:
V1: EH 12AX7, or chinese
V2: Groove Tubes Mullard RI 12AX7
V3: Watford Valves Harma STR 12AX7
V4: Golden Dragon 12AX7A
V5: Mullard CV4024 (12AT7 equivalent)


Very close to yours, it seems...

 

I have come across people that don't exactly dig that box. I use Hotplates pretty successfully. But still, if you attenuate down to conversational volume you usually have a tonal compromise. One trick with the Hotplate is that you can run it as a load, and take the line out into a solid state (e.g. PA) amplifier and eq that. That gives really good tone at any volume. Of course, you need the clean amp as well.