Lifco 630-2 Reverb Information Request

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Does anyone out there happen to have a (Regal) Lifco 630-2 amp such that they could help to trace out a few connections on it?

The "Lifco 630" seems to have 4 inputs, but no reverb.

Tube lineup = 4x 6AV6 (3 pre-amp, 1 tremolo), 2x 6BQ5 (output) and a 5Y3 rectifier.

The "Lifco 630 2" (which I have) takes 2 of the general inputs away, but adds a spring reverb circuit with a 12AX7 and 6BM8.

The problem I have is that the previous owner of the amp removed all of the electronics associated with the spring reverb. I’d like to restore it back close to original operation - or at the very least have it operate as the original did.

To that end, does anyone happen to have a 630-2 such that they’d be able to trace out the connections for the 12AX7 and 6BM8? (Based on the photos at http://music-electronics-forum.com/t23663/ it looks like half of the 12AX7 is unused - but there’s no way to tell the interconnection of the 6BM8. It also seems like the 6BM8 is used in the drive cct. and the 12AX7 is in the recovery, but I’m not sure of that).

Failing being able to trace out the actual wiring, does anyone have specific experience with this amp/amp-head such that they can describe how the reverb interface ‘works’? E.g., there is a separate “Reverb Input” jack. Is that the only way to have reverb added in, or will the main channels route through the reverb if there’s nothing specifically connected to the reverb jack? Does the reverb output only get added in post tone-stack or can the 'verb'ed signal also be modified by the tone controls?

[clank]

I have one of these and can post pics for you. I also found a schem for YGM-1 on this site that might be helpful. Not sure it is exactly the same but I do believe the 630-2 is a copy of the Traynor. I am only now looking into why my reverb and trem are not working (the amp was packed away for more than a year). All tubes tested good, no visible signs of problems with wiring or resistors/caps. The amp works although I'm not sure it's as loud as it should be and even cranked full there is virtually no breakup/crunch in the sound that I was hoping for. Doesn't seem right from what I have read about the sound of these amps. Not sure if you have to have something plugged into the foot switch jack, or reverb input jack for these to work? Maybe a user manual for a YGM-1 would help me understand how to operate this thing but I can't find one on the net. I have read a common fix for this problem is to replace a resistor. Can anyone lead me to where that resistor that is? Any other suggestions of things to check?
thanks

[clarked]

Thank you for the reply.

While I’ve also seen references that suggest the 630-2 is a copy of a Traynor, I’ve not seen any actual Traynor amps or schematics that really 100% match. For instance, the YGM-1 uses both sides of a 12AX7 to drive the reverb tank whereas the 630-2 appears to uses a 6BM8 to drive, with half a 12AX7 in the recovery circuit.

From what I’ve seen, the 630 (without the reverb) is effectively the same as a Beltone AP22 or AP24. The 630-2 appears to the same as the 630, but with two of the inputs dropped, a different setup for the on/off switch, and then reverb added (two tubes + transformer + tank + a defeat switch) and another tap off the power supply.

I’ve posted a copy of my draft schematic here:
http://web.ncf.ca/ac151/LIFCO630_2_Draft03.pdf

I’m reasonably confident about most things on the non-reverb section of circuitry - but I’ve had to make some reasonable guesses for everything relating to Reverb, from the jack right through. Also, some of the values around the 6BM8 and 12AX7 are likely a little different than the original design owing to the fact that the original reverb tank and transformer were missing from my unit (and so I’ve fitted in a MOD reverb tank as a replacement).

The foot switch allows you to remotely turn off/turn off the reverb. You shouldn’t need anything in that jack for proper operation - but if you’re not getting any reverb you might want to check to confirm that the tip of jack isn’t somehow shorted to ground.

I do expect that in order to get any reverb you need to be plugged into the Reverb jack, and to have the reverb amount turned up. If the reverb amount is turned down - or if you’re just in one of the normal instrument jacks - you won’t get any reverb out.

You should be able to get tremolo for either the standard instrument input or the reverb input. To get any, the Tremolo switch needs to be turned on. If the tremolo doesn’t work at all (and if the tube is fine) I’d be looking to confirm that the voltage levels change with the trem switch.

The separate numbers on the schematic (like the "1.4" at V3) is the DC voltage measured at that point during normal operation. These may help in debug, to see if a cap/resistor has failed.

If there is a chance to poke into the system there, I would be very interested in receiving any updates/corrections to the values/location of values in the draft schematic. Of particular interest are:
- Wiring and values of components in the Treble and Bass sections (esp. including the actual pot values)
- actual wiring/location of the Reverb on/off footswitch into the 12AX7
- actual components present between the output of V11 (12AX7) and the input to V3.
- confirmation of wiring/connection of Reverb Input jack into the rest of the circuit.

If it is easier to just take some close up pictures, then just let me know and I can look to extract the values from those.

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Hopefully these help

[clarked]

It looks like perhaps only one picture actually got attached (at least I can only see one in the posting). If possible, the desire would be to either validate the wiring noted in the schematic, or to get some photos of the noted areas, but clear enough that the component values/connection points can be confirmed. While perhaps not of the tone and reverb areas of the 630 2 - these are the sort of images that would be good:

http://web.ncf.ca/ac151/630_1.jpg
http://web.ncf.ca/ac151/630_2.jpg

[clank]

not sure why, but the attachments didnt seem to work. The pictures are not very good, but hopefully you can see what you need.

[clank]

My ability to make sense of schematics is limited, but I will try and look closer. It will hopefully help me get my reverb and trem working. I am comfortable poking around inside the amp. The recovery side of reverb is working. I can hear the crash. I tried a different tank also had the same result.The trem problem, I have no idea. Any idea of the year of this amp?