gs5556

Responses from gs5556

Test and repair amp
Pyramid Audio down in Austin. Ask for Chris. 
Preamp/interconnects cause amp problems?
Popping sound in the speakers is dc. The amp either has a transistor problem, which is easy to find, or a short at the output caused by a wire or component fault, which is difficult to find. Could be carelessness in manufacturing in which case it’... 
Is it safe to use a higher amperage rating fuse?
If fuses are not manufactured correctly they will trip when they’re not supposed to. It’s no surprise the boutique fuse salesmen do not provide time current curves or melting energy. Going up in fuse sizes increases the probability of excessive he... 
How far over the limit can I go
Have the same set of tubes in my CAT preamp since 2016, about 10,000 hrs. Still going strong. (Mullard 12AX7 reissue, Reflektor 6922). The answer is they could fail tomorrow or not. 
Detecting “Dirty” Power
Start at step one: lift the ground of the amp by using a two prong cheater plug. If the hum goes away then it’s a ground loop. 
I am getting some new tubes for my amp, and I want to do a 24-hour burn in. How?
Playing a signal through the tube for twenty minutes will do a lot more than running it idle for 24 hours. Just turn on the amp and play music. 
Need help with a 6AS7 Headphone Amp
Measure the voltage from circuit ground to earth. If it’s only a few tens of millivolts put a 10 ohm resistor in parallel with a 0.63 uF film cap between circuit ground and earth to lift ground a few volts. That may help. 
Onkyo P-308 recapping/upgrading
If it works, leave it alone.Kudos to that repair shop. 
Current...
Yes.I = sqrt(300/8) x 2I = sqrt(490/4) x 2 
I just bought a Steinway which sounds like a banjo.
Even the cheapest of the cheap speakers will differentiate a Steinway from a banjo. 
Why would anyone want class AB amp when class A always sounds better ?
Class A amps (almost) always measure better, not sound better. 
Other Rectifier tubes Alternative for 5AR4
The 5AR4 has a very low forward voltage drop for a given plate current. Substituting another rectifier may likely  cause a  B+ voltage sag which may affect performance. That’s probably why Luxman doesn’t give you other choices. Safety wise it’s no... 
Soldering Panel mount Rca
There is a channel or a slot on the back. Fill it with solder and attach the wire. 
Rebuilding Power Amplifier(s)
Without a schematic and test equipment you will have quite the challenge. Just like repairing a car, success depends on identifying the problem -- not throwing parts at it. In both cases you need diagnostic equipment to identify the problem and th... 
Power transition
Look in your owner's manual. If it the voltage is field convertible, then follow the instructions. If it is factory set, then call McIntosh.