Question for pre-500 RF-1C owners

[AdmiralB]

Does the loop bypass work the way it's supposed to?

I believe it does not, and that's why rev C was so short-lived. I'm working on one now, and the loop has been driving me nuts - it's always on.

Going by the schematic for the rev F (and my experience with rev D), when the loop is in bypass mode, none of it is supposed to be active - the relay (relay 2) completely bypasses the entire circuit, including the loop master. Signal is taken from the channel masters directly to the phase inverter.

When the loop is on, the relay feeds signal from the master volumes into the loop, the returns the signal from the loop master to the phase inverter.

When the loop is set to footswitch, or it's on on only one channel, it works as above when engaged, but when it's not engaged LDRs in the loop bypass the send and return jacks, but the send level control and loop master are still active.

Well, the PCB for rev C is made wrong. All the modes work as intended EXCEPT bypass - the relay never closes to bypass the loop, because they wired up the coil polarity wrong. When the loop selector is in bypass mode, the loop master and send controls are still active.

Can anyone who owns a rev C dispute this? Is your lead master bypassed in any setting?

 

[LynchLicks]

Sorry I don't have an answer to your question but I have one I'd like to ask myself.
Do you know what Rev the board would be on DR #220 & #414?
I don't particularly like the sound of either amp with the loop on so I just run them both dry and they both sound awesome. Both sound exactly the same to me tone wise loaded with same type of tubes(6L6's)
How many Revs were there within the first 500 DRs?
And does this really make that big of a difference in tone from Rev to Rev and how the effects loop functions within the first 500 DRs? Thanks!

 

[siggy14]

The 414 is defintly a rev D, more then likley 220 is also if they sound exactly alike.

Sorry I don't have an answer to your question but I have one I'd like to ask myself.
Do you know what Rev the board would be on DR #220 & #414?
I don't particularly like the sound of either amp with the loop on so I just run them both dry and they both sound awesome. Both sound exactly the same to me tone wise loaded with same type of tubes(6L6's)
How many Revs were there within the first 500 DRs?
And does this really make that big of a difference in tone from Rev to Rev and how the effects loop functions within the first 500 DRs? Thanks!

 

[AdmiralB]

220 would be a C. The amp I'm working on is a little higher than that.

 

[Elpelotero]

Sorry I don't have an answer to your question but I have one I'd like to ask myself.
Do you know what Rev the board would be on DR #220 & #414?
I don't particularly like the sound of either amp with the loop on so I just run them both dry and they both sound awesome. Both sound exactly the same to me tone wise loaded with same type of tubes(6L6's)
How many Revs were there within the first 500 DRs?
And does this really make that big of a difference in tone from Rev to Rev and how the effects loop functions within the first 500 DRs? Thanks!

2 revisions within first 500. C and D. Although #1-5 may possibly be A or B. The two amps should not sound *exactly* the same. The 220 should be brighter and a little more "brash" when playing rhythm. You have to tame it with the presence knob. The loop function does not really affect the tone that much between revisions.


To the original poster, I can get my effects loop to work perfectly. It does take some getting used to knowing what knobs to press, but once you get it everything works (for me at least). I notice no change in tone when I engage the loop as long as there is a high amount of volume versus disengaging the loop and using the channel master. My typical settings are Loop Active Master at 12, channel master at 9-11, and the Send knob at 4-5. It works great with a Pod XT.

I understand what you are saying though. I have never tried bypassing the loop and turning the knobs to see if they still affect the amp, which is what should happen if what you are saying is correct.

I would suggest you call the factory today (they're closed tomorrow) and ask for Mike Bendinelli. He did the final inspection on a lot of the Rev.C's and can probably tell you more than we can. The circuitry of these amps is still a little cloudy to many users, as opposed to something like the Mark2C+ which has been around for decades. The pre500s have only received attention in the last year.

 

[Kung-Fool]

Mine works fine. I have R-0028.

 

[AdmiralB]

What works fine?

Can you confirm that when the loop is set to bypass on the back panel, the loop master has no effect?

 

[siggy14]

you mean 1-4 might be Revision A or B, remember I have number 5 and it is a revision C

Sorry I don't have an answer to your question but I have one I'd like to ask myself.
Do you know what Rev the board would be on DR #220 & #414?
I don't particularly like the sound of either amp with the loop on so I just run them both dry and they both sound awesome. Both sound exactly the same to me tone wise loaded with same type of tubes(6L6's)
How many Revs were there within the first 500 DRs?
And does this really make that big of a difference in tone from Rev to Rev and how the effects loop functions within the first 500 DRs? Thanks!

2 revisions within first 500. C and D. Although #1-5 may possibly be A or B. The two amps should not sound *exactly* the same. The 220 should be brighter and a little more "brash" when playing rhythm. You have to tame it with the presence knob. The loop function does not really affect the tone that much between revisions.


To the original poster, I can get my effects loop to work perfectly. It does take some getting used to knowing what knobs to press, but once you get it everything works (for me at least). I notice no change in tone when I engage the loop as long as there is a high amount of volume versus disengaging the loop and using the channel master. My typical settings are Loop Active Master at 12, channel master at 9-11, and the Send knob at 4-5. It works great with a Pod XT.

I understand what you are saying though. I have never tried bypassing the loop and turning the knobs to see if they still affect the amp, which is what should happen if what you are saying is correct.

I would suggest you call the factory today (they're closed tomorrow) and ask for Mike Bendinelli. He did the final inspection on a lot of the Rev.C's and can probably tell you more than we can. The circuitry of these amps is still a little cloudy to many users, as opposed to something like the Mark2C+ which has been around for decades. The pre500s have only received attention in the last year.

 

[AdmiralB]

OK, I got an answer. It works...IF you use relays with non-polarized coils (or, in essence, switches that are omnidirectional).

This amp has (had, now) a standard polarized relay in the loop slot. Learn something new every day.

 

[Elpelotero]

you mean 1-4 might be Revision A or B, remember I have number 5 and it is a revision C

Sorry I don't have an answer to your question but I have one I'd like to ask myself.
Do you know what Rev the board would be on DR #220 & #414?
I don't particularly like the sound of either amp with the loop on so I just run them both dry and they both sound awesome. Both sound exactly the same to me tone wise loaded with same type of tubes(6L6's)
How many Revs were there within the first 500 DRs?
And does this really make that big of a difference in tone from Rev to Rev and how the effects loop functions within the first 500 DRs? Thanks!

2 revisions within first 500. C and D. Although #1-5 may possibly be A or B. The two amps should not sound *exactly* the same. The 220 should be brighter and a little more "brash" when playing rhythm. You have to tame it with the presence knob. The loop function does not really affect the tone that much between revisions.


To the original poster, I can get my effects loop to work perfectly. It does take some getting used to knowing what knobs to press, but once you get it everything works (for me at least). I notice no change in tone when I engage the loop as long as there is a high amount of volume versus disengaging the loop and using the channel master. My typical settings are Loop Active Master at 12, channel master at 9-11, and the Send knob at 4-5. It works great with a Pod XT.

I understand what you are saying though. I have never tried bypassing the loop and turning the knobs to see if they still affect the amp, which is what should happen if what you are saying is correct.

I would suggest you call the factory today (they're closed tomorrow) and ask for Mike Bendinelli. He did the final inspection on a lot of the Rev.C's and can probably tell you more than we can. The circuitry of these amps is still a little cloudy to many users, as opposed to something like the Mark2C+ which has been around for decades. The pre500s have only received attention in the last year.

correct. I knew someone had #5! temporary brain fart. I've seen pics of #1, but don't know the revision.

 

[Kung-Fool]

What works fine?

Can you confirm that when the loop is set to bypass on the back panel, the loop master has no effect?

Yes. That is what we're talking about.