Products that are not repairable by Dr Rock

Please contact the manufacturer

1. Line 6

2. Blackstar

3. Berringer

4. Mackie

5. Carvin

6. All powered PA speakers

7. Any Class 4 or Class D digitlly powered amplifiers

8. Fender amps manufactured with these Trouble LEDs: The Twin, Pro, Concert

Dr. Rock Amp Repair Sacramento 


All amplifier repair is $70 per hour, and are estimated at 2 hours labor + parts, or up to $220.00.

There is a $70 deposit applied to the service, and repairs may be less than the estimate. If the service looks like it will exceed the estimate, Larry, AKA Dr Rock,  will call you with a revised estimate and you can approve or decline from there. If declined, where replacement makes more sense than repair, he’ll just button it up and return it to you at the shop, and all it costs you is the $70 deposit.

Average turnaround time is 7 to 10 days.


I am constantly asked what I charge to re-tube and bias an amp. This question raises many more because it means that whatever is going on with that person’s amplifier, they have reached the conclusion that the tubes are the problem, that changing them will fix it, and they want to do that at the lowest possible price. 

I am all for doing stuff at the lowest possible price, which is why I shake my head every time I get an amp in for repair after the owner has spend $200 on a full set of new tubes and still has the original problem. I guess it’s human nature to feel more comfortable buying a part than paying for labor, but throwing a full set of tubes at an amp in the hopes it will fix a problem is not your lowest cost option for repair.

Fact: The large format output tubes, 6L6′s, EL34′s and the like, have a designed life span of 10,000 hours (do the math for your usage. At 10 hours a week, that’s 19 years). At the end of that time, the tubes aren’t dead, but output has degraded to 70.7% of the designed level.

Preamp tubes do not push speakers and move air, and can last even longer.

That said, all tubes can be mechanically damaged from being bounced around in transit, or exhibit manufacturing sample defects. Preamp tubes can develop static or microphonics (ringing). Power tubes can develop internal shorts and glow red or blow fuses.

At Dr. Rock, we will only replace defective tubes because you won’t hear any difference if we replace a good working tube with a new one. We don’t carry cheap tubes, either. We only sell the best tubes available, selected for low noise, matched for output and backed by Ruby Tube’s full 6 month warranty when installed by us.


You’ve used the rest, now hire the best, Dr. Rock.

Tube Talk with Dr. Rock

3248 J Street

Sacramento, CA 95816

916 - 441- 6555