Gain circuitry question 2 ch DR rev g - repair update!

[clutch71]

OK, I've had my 2 ch DR for about two months. When I was trying the amp out the guy I bought it from claimed to run the gain maxed all time since he purchased it in 2000. It had Sovtek 5881WXT+ power section, Sovtek 7025/12AX7WA in the preamp section. He claims these tubes were purchased several months prior to my purchase and barely played.

To get the a decent saturation I also have to run the gain maxed with that tube configuration. The Sovteks sound a little dark and harsh to my ears. I also found that no matter how I tweaked the vintage I didn't get a sound in that mode that I really like. The cleans are dark but decent for a DR.

I replaced the Sovtek preamp section w/ a Mesa SPAX7 in V-1 and Mesa 12AX7 V-2-V5 leaving the Sovtek 5881WXT+ in the power section. The saturation is a little smoother (not what I'm looking for) but I'm still almost maxing out gain. Vintage is a little more usable but I'm still not happy with it.

My questions are this...
1) Could running the gain maxed damage the gain circuitry somehow?
2) If so, is it time to have the amp gone over by a technician?
3) Is the power section still influencing the gain structure with what I'm experiencing?
4) Is this just a matter of finding the right tube combination of tubes to fit what I like?

I'm happy with the DR features over my old ROV but I don't quite have the sound I'm looking for. The combination I had in the ROV when I sold it was a JJ 6l6's in the power section and Groove Tube silvers V-1-V4 and a JJECC83 V-5.

It was a nice smooth saturation that I really liked, great cleans; Vintage and Modern were extremely usable. It just didn't have the "boominess" or the "compression" of older 2ch DR's I've played.

I know that "smooth" and "compressed/tight" are not always synonymous with DR's. I'm referring to these terms by Recto standards. I plan on picking up either a Mark IV, Mark III, or Triaxis/2:90 next year and running a two rig system with some sort of channel switcher.

Sorry so long but I just wanted all variables on the table for assistance with questions 1-4.

Ciao

 

[kramerxxx]

I have a newer Dual Rec but it should be close enough for comparison.

I run gain about 1pm or just a little over straight up and get plenty of crunch, sustain and drive on channels 2 and 3.

You will find the DR comes to life when you are giving the power section some work to do. I set my amp master at noon and dial up the channel masters to the volume level you need. DR sound buzzy when played at really low volumes. If you need a saturated sound at a very low volume to practice I would recommend a good overdrive pedal. I know this sound odd but you have to remember DR were designed with the volume being at performance levels, not bedroom level. YMMV

The power tubes will change the voice a little but not as much as the other points I've mentioned above so I would change the tubes when they are needed, not to try and get more gain.

 

[clutch71]

Kramerxxx, Thanks for the reply. I know Mesa's need to be cranked to get good saturation and normally you can dial the gain back at higher volume. Not with this amp though. I should probably have mentioned that. 2ch do get better tones at lower volume IMO.

I have several clips on youtube that might help diagnose this situation.

http://www.youtube.com/profile?user=dwq1971

The 2ch auditorium clips are cranked (near "concert" volume with the LAM engaged send around 75% with the LAM and Master set at 12 o'clock) tones with the gain maxed all the way to the right. You'll note I'm standing way to the left of the amp to spare my ears a little.

The two 2ch clips in the garage clips are "lower level" clips with the LAM engaged send around 100% with the LAM and Master set at 8 o'clock w/ the gain maxed. Not "bedroom" volume but not near as loud as the auditorium clips.

My old ROV was never, at any volume, pushed w/ the gain past 2 o'clock in Modern or 3 o'clock in Vintage.

 

[Elpelotero]

the power tubes could have a very cold rating, which forces you to crank the thing more.

Try getting a single pair of power tubes of your choice that are rated anywhere from medium to hot. (about 6-10 on groove tube scale). These may do the trick for you.

Or you can take the tubes to your local tech so he can measure what they are putting out.

 

[Silverwulf]

Interesting...I play metal, and my band plays in the vein of old Metallica, Iron Maiden, etc...with some modern influence like Shadows Fall or Killswitch Engage tossed in on occasion. I never run the gain on my '94 Recto higher than 12 noon or slightly above and it's plenty of gain to play music as mentioned above. If you have to crank it to max to get saturation, you have some issues somewhere.

 

[Kung-Fool]

You shouldn't have to max the gain for those tones. I can get those with both of my 2 channels (rev C & rev G) with the gain around 12:30-1:00 regardless of volume. I would try a complete retube. Either something is wrong with those tubes or something is wrong with the amp.

 

[JerryFJA]

Has the amp been modified? There's a shop out there doing mods that neuters them and takes away the brutal qualities.
Running the gain all the way up won't hurt the amp at all, just your ears! :wink:
I would say your situation is more than just a tube issue. A weak preamp tube could cause low gain, but it sound like you've changed them all.
It can't hurt to have it looked at by a tech to verify everything is in order. That would be the first thing I would do once you've checked the basics like your tube, guitar, and cables.
Jerry

 

[clutch71]

Just got the amp back late yesterday. Only had a short time to tinker with it but the difference was profound. They replaced a grid resistor and it now responds like any other DR I've played. The Vintage is now usable.

I'm going to throw the Groove tube LS Q's in when I get home. Still not that wild about the Sovteks and think I'm going to replace them with a Mesa power section.

Big shout out to the guys at Lang music who play tested, agreed there was something off, and corrected the issue.

I contacted Mesa who really just said send it in. Shipping + $100 dollar bench fee. The guys at Lang took care of it for $66 out the door. Not knocking Mesa just pointing out that if your local Mesa tech is good go with it.

Thanks for all that commented!

 

[Elpelotero]

glad it all worked out for you man! amazing how such a small thing can mess it up so much.