Recent content by tbonesullivan

I'm pretty sure that V4 (as well as V1) are only used by the Rhythm channel, so with that a good tech should be able to isolate the hum. The amp is definitely old enough to have some of the electrolytic caps, resistors, etc develop problems.

This is definitely true. Lots of EL84 designs out there now, especially from Friedman. A JEL-20 is on my short list. Sure I'd love to have a JEL-100 but those are HUGE, and the sounds they have been able to get out of the smaller amps are really something else.

Maybe, but back when it came out, it was 1994, two years after the "Solo Head" Dual Rectifier came out, and about a year after the Trem-O-Verb. It had the same switchable rectifiers, used the same foot switch as the Solo Head and Tremoverb, and was pretty much set up the same way. It was a...

People have asked the same question about the Maverick and Blue Angel as well. It could just be that everyone who wanted that kind of amplifier already got one. The badlander seems to be almost a stripped down Rectifier intended for home direct recording, and one voiced so that it wouldn't...

That's definitely odd. I know that the RFT EL34s don't like high plate voltages. Are there any specific limitations on the preamp tubes? I would assume if an old production tube can get toasted by V1, then the new production tubes would be dying all over the place.

That looks to be a Three Channel Non-Multiwatt, so yes, it has the Parallel effects loop. The "SEND" Control is in the circuit regardless of whether the effects loop is assigned to that channel and/or activated with the foot switch. Do the effects you are using have a "100% wet" option?

What is the SEND level at in the rear? That is always in the circuit, so if you have the send set really low, you'll have very low output. I usually keep it right in the middle.

I have a few 5751 tubes that I sometimes use when I want less gain. I think they have a 70% amplification factor, but the other specifications are about the same as a 12AX7.

Well, what are the other settings? How loud is the amp? Where are the treble and presence set at? Do the controls have any influence on the noise?

I'm not an expert, but if there is dust and oxidation on the tracks, rubbing the wiper back and forth without cleaning / lubricating it sounds like it might have a detrimental effect on the service life of the pots.

Definitely sounds like dirty pots. Was it kept covered? You'd be amazed how dust can get inside things over time. Cleaning the pots normally isn't hard, but inside a Mark V 90, getting access can be a PITA.

Yeah, and especially if the gain control scales different between modes, it'll continue to be. It would need to be redesigned somehow, maybe by having a relay to control the electronics around the master for that channel. But that opens up a whole new can of worms.

To quote the hunt for Red October "Sure you could, but why would you want to?". I can only think of amps like the Electra Dyne and Royal atlantic, which were specifically designed to "work" well switching modes, and even with that they have some type of compensation. Without any ability to...

I watch a lot of amp repair videos, and all that most use on the video is isopropyl. I think naptha would also be good, though definitely not as "harmless" as isopropyl in terms of exposure. I mean you could probably also use straight ethanol as well.

Well actually they should have called the Triple Rectifier the Quadruple rectifier! And the Dual Rectifier the Triple rectifier. Jeez, give it a rest. Are you going to go after Fender next, claiming that the "Deluxe Reverb" is not really "Deluxe"?