My amptech saw my dead RM100. He was startled. DESIGN FLAW!

[Julia]

I run mine pretty balanced. No squeals. But then I don't play high gain. And I use a gate/compressor/limiter in the loop.

 

[m0jo]

Hmm the difference might be that I run an RM4 and RT2/50 setup.
But I can dime my modules or my master both and there's no squeels or weird noise at all.
With the modules dimed it seems to have a but less compression, but it's also harder to tweak the volume changes..

I have yet to overdrive my MX200 ..

 

[Voodoo Amps]

i talked with Voodoo Amps on this. They suggest bigger Transformer so that doesnt happen.

basicly they're saying:
"after buying a randall, you need to rip out the tranny for a better one or it blows up"

While upgrading to a higher quality power transformer will give you a better tone, a lower noise floor and easier to play/smoother feel, it will not prevent high voltage arching on a printed circuit board. For that you will need Corona Dope.


Hope it helps

Hey Trace,
WTF is Corona Dope? And how do you use it? I am assuming you aren't reffering to snorting Mexican beer. I suppose that it is a insulating layer that allows better electrical isolation between traces. Let me know, bro. Peace :shock: :shock:

Corona Dope is used to prevent arching and is very effective. We use it on the RM100's we Mod and any other amps where high voltage traces are very close to ground traces, etc. Thus far there have been no issues with arching on any of the RM100?s we have Modified.


Have a great Monday;
Trace

 

[Bewitagos1]

i talked with Voodoo Amps on this. They suggest bigger Transformer so that doesnt happen.

basicly they're saying:
"after buying a randall, you need to rip out the tranny for a better one or it blows up"

While upgrading to a higher quality power transformer will give you a better tone, a lower noise floor and easier to play/smoother feel, it will not prevent high voltage arching on a printed circuit board. For that you will need Corona Dope.


Hope it helps

Hey Trace,
WTF is Corona Dope? And how do you use it? I am assuming you aren't reffering to snorting Mexican beer. I suppose that it is a insulating layer that allows better electrical isolation between traces. Let me know, bro. Peace :shock: :shock:

Corona Dope is used to prevent arching and is very effective. We use it on the RM100's we Mod and any other amps where high voltage traces are very close to ground traces, etc. Thus far there have been no issues with arching on any of the RM100?s we have Modified.


Have a great Monday;
Trace

I wouldn't recommend this as a do-it-yourself repair though unless you've worked with the stuff in the past. Send it to Trace or someone with experience, once its on, it isn't coming off easy.

 

[Voodoo Amps]

i talked with Voodoo Amps on this. They suggest bigger Transformer so that doesnt happen.

basicly they're saying:
"after buying a randall, you need to rip out the tranny for a better one or it blows up"

While upgrading to a higher quality power transformer will give you a better tone, a lower noise floor and easier to play/smoother feel, it will not prevent high voltage arching on a printed circuit board. For that you will need Corona Dope.


Hope it helps

Hey Trace,
WTF is Corona Dope? And how do you use it? I am assuming you aren't reffering to snorting Mexican beer. I suppose that it is a insulating layer that allows better electrical isolation between traces. Let me know, bro. Peace :shock: :shock:

Corona Dope is used to prevent arching and is very effective. We use it on the RM100's we Mod and any other amps where high voltage traces are very close to ground traces, etc. Thus far there have been no issues with arching on any of the RM100?s we have Modified.


Have a great Monday;
Trace

I wouldn't recommend this as a do-it-yourself repair though unless you've worked with the stuff in the past. Send it to Trace or someone with experience, once its on, it isn't coming off easy.

Agreed, if you are inexperienced with using Corona Dope it would be best to take your amp to a qualified repair tech. We are happy to fix/repair any RM series, etc. or apply it as a preventative measure. If anyone has any questions please feel free to call or email me directly ([email protected]). I'm always happy to be of help.


Have a great Tuesday!
Trace

 

[skunky_funk]

Necrobumping... My amp is blown (again) but I haven't seen the guts yet. All I know is one of my JJ EL34s literally shattered and the plates are exposed now. :roll:

 

[wakeguitar]

interesting...

 

[eyeball987]

Necrobumping... My amp is blown (again) but I haven't seen the guts yet. All I know is one of my JJ EL34s literally shattered and the plates are exposed now. :roll:

JJ has had a bad run of 34's over the past few years. They have caused lots of failures. The big manufacturers and tube vendors have verified this. Just an FYI.

 

[Julia]

I won't touch EL34s with a ten foot pole. Love the sound. Hate the maintenance. 6550Cs for me. I can't play that loud so no power tube breakup anyway.

 

[skunky_funk]

Necrobumping... My amp is blown (again) but I haven't seen the guts yet. All I know is one of my JJ EL34s literally shattered and the plates are exposed now. :roll:

JJ has had a bad run of 34's over the past few years. They have caused lots of failures. The big manufacturers and tube vendors have verified this. Just an FYI.

I've also experienced that too... the E34Ls, the EL34s; THE FAILURE RATE IS HUGE. I don't know with KT77s but I think I'll give the new Tung Sol EL34Bs a run for my money.

 

[eyeball987]

Necrobumping... My amp is blown (again) but I haven't seen the guts yet. All I know is one of my JJ EL34s literally shattered and the plates are exposed now. :roll:

JJ has had a bad run of 34's over the past few years. They have caused lots of failures. The big manufacturers and tube vendors have verified this. Just an FYI.

I've also experienced that too... the E34Ls, the EL34s; THE FAILURE RATE IS HUGE. I don't know with KT77s but I think I'll give the new Tung Sol EL34Bs a run for my money.

I use winged C's but with the recent price increase, I hear good things about the Ruby STR's I believe they are called. The Tung Sol's get good reviews too. I would try them too.

 

[GuitarGod87]

Remember I posted a thread asking for help on my dead RM100. To make a long story short, I kept blowing HT fuses (used to be 250mA and replaced them with 315mA), and eventually, two 1.6A internal fuses blew. Replaced the two 1.6A fuses with 2.0A ones, and then, my amp had a spark. The pic above shows what happened.

My amptech is here and is STARTLED. WHY DID RANDALL/EGNATER DESIGN THOSE HIGH VOLTAGE TERMINALS BESIDE THE GROUND? Look at the pic... the brown wire with the spade connectors is connected to the output tranny. You're talking about 400V around the ground. Once that arcs (shorts), you're in for trouble.

The same thing happened to the red wire. Sparks due to arcing. Now I had them jumpered direct to the tube socket.

He was surprised about the design flaw of the RM100. Oh well. I still love it though.

What were the characteristics of your dead amp? I mean, did you any sound out of it when the volume was cranked? I was playing today and I unplugged my guitar cable to tune up and didn't switch the stand by switch. When I plugged back in the amp popped and was dead. I can get a very low level sound if I strum hard enough. Other than that the amp isn't working. It turns on and plays fine for about one minute then dies again. I spoke to Voodoo amps and they mentioned your scenario and told me it could be the power section arcing and that it may burn the board up. I'm asking for the characteristics of your dead amp to compare to mine. I'm sending it in to the bench tomorrow anyway.

 

[skunky_funk]

Remember I posted a thread asking for help on my dead RM100. To make a long story short, I kept blowing HT fuses (used to be 250mA and replaced them with 315mA), and eventually, two 1.6A internal fuses blew. Replaced the two 1.6A fuses with 2.0A ones, and then, my amp had a spark. The pic above shows what happened.

My amptech is here and is STARTLED. WHY DID RANDALL/EGNATER DESIGN THOSE HIGH VOLTAGE TERMINALS BESIDE THE GROUND? Look at the pic... the brown wire with the spade connectors is connected to the output tranny. You're talking about 400V around the ground. Once that arcs (shorts), you're in for trouble.

The same thing happened to the red wire. Sparks due to arcing. Now I had them jumpered direct to the tube socket.

He was surprised about the design flaw of the RM100. Oh well. I still love it though.

What were the characteristics of your dead amp? I mean, did you any sound out of it when the volume was cranked? I was playing today and I unplugged my guitar cable to tune up and didn't switch the stand by switch. When I plugged back in the amp popped and was dead. I can get a very low level sound if I strum hard enough. Other than that the amp isn't working. It turns on and plays fine for about one minute then dies again. I spoke to Voodoo amps and they mentioned your scenario and told me it could be the power section arcing and that it may burn the board up. I'm asking for the characteristics of your dead amp to compare to mine. I'm sending it in to the bench tomorrow anyway.

Have you checked the 4 HT fuses at the back? The first batch of RM100s shipped with 250mA fuses, but eventually Randall said they're safe with 400mA fuses. If you've got a bad tube, the HT fuse of that particular tube will blow.

In my case, it as very different. The power amp is completely dead. The internal fuses were blown. And had to replace some resistors, and also had my tech fix the grounding issues of the PCB.

 

[GuitarGod87]

Well it cooled down and turned back on, but I've heard of RM100's doing that then totally blowing a few jams later. I would like to hook our techs up because I really like my tone and I don't want to sell my amp once i repair it. So I would like my ground flaw looked at as well. Anyway, my amp just popped then very little sound was coming out. After about two hours pass, I played it again and it worked for about a minute. So I tried it again another couple of hours later and it played fine. I'm still taking it in tomorrow. Who's your tech?