Probably been done before fender tremolo in a bluesbreaker substitution

[Phil_S]

VTL5C1 Vactrols are getting scarce. I found one source, about $10 plus shipping. VTL5C3 can be found for $2-ish. Is this an appropriate substitute? How about other LED-based opto-couplers? If I just Google Vactrol VTL5C1, it returns other part numbers like Silonex NSL 7053 or Phtonix NSL 32SR3. I don't understand the specs adequately to know what qualifies as a sub. Here's the second one: https://www.digikey.com/product-detail/ ... ND/5039793

See page 48 for the VTL5C1 spec and page50 for the VTL5C3 http://pdf.datasheetcatalog.com/datashe ... /VT500.pdf

[sluckey]

VTL-5C3 doesn't work as well as the VTL-5C1. Very different specs. There are plenty of current production VTL-5C1s that seem to work just fine. AES has them for $8.

[stukidboy]

Thanks for all of your help and suggestions.

Mr. Sluckey's trem-o-lator is perfect and works really....pretty danged well.
Almost nah nah, but not quite, perfect.
A little reverb and it get close to an echo effect.
I have no idea how you figured that out, but it is pretty dern slick

I, also, found your suggestion of the treble wiper right on the money.

Changing it to either, other, source, was always worse than the wiper.

I am very happy, as is my buddy/client

and only half a tube.

Now, can you show me how to use that half tube for extra gain?
I added a pot, just for that. (on my personal bluesbreaker [I'll load some pics]....single channel, tremolo, with switches for brightness, bass boost, and HI/LO impedance switch)
I left the gain pot, hoping to implement it, at some point.
it, and probably most of my amps will l have this mod done (tremolater), since I bought 10 of those opto isolators, opticouplers....diode light resistor(solar cell) thing


But that is probably another post.

THANKS! Sluckey.

(actually I was 1 solder joint away from the conclusion, but you pointed the way.)
I will send pics of my work, before cleanup.
I let it get back in his hands before I got pics, finished, but the parts are in place, correctly.
I checked it out for about 30 minutes, out it back together, and as I was handing it to him, realized I hadn't taken those pics.
whoops!

If I am slow loading pics, it is because I am old.

remind me......it's ok...

[sluckey]

Now, can you show me how to use that half tube for extra gain?

It's OK to have a wasted half tube.

[Colossal]

Hello Steve,

In reviewing your PDF documenting your Bandmaster and Trem-O-Nator circuit, I noticed that the layout calls for a 250k linear Intensity pot, but the schematic shows 50k (doesn't specify audio/log or linear). 10thTX's schematic posted earlier shows 50k, but his layout shows 50k-RA. Could you please clarify the correct value for this pot?

Thanks,
Dave

http://sluckeyamps.com/misc/bandmaster.pdf

Here is the layout:

Layout.png

...and a comment says 50k should be 250k

comments.png

10thTX's and your schematic showing 50k

10thTXScheme.png

sluckeyscheme.png

10thTX's layout showing 50k-RA

10thTXLayout.png

[Phil_S]

Now, can you show me how to use that half tube for extra gain?

It's OK to have a wasted half tube.

FWIW, I agree, it's not an expensive tube. There's no "tone" running on this tube. Get a cheap Sovtek or something. OTOH, if you really feel that bad about it, use a 6AV6, which is a 7 pin, small bottle tube, that is exactly one half of a 12AX7. Ignore the double diode that's inside the bottle.

Shazam, look at this deal! https://www.ebay.com/itm/6AV6-Philips-E ... SwZ39fOV8i The real problem is chassis real estate and heater supply. If you built an amp around these, you'd need 2x the number of tube sockets (or, in this case, 2x - 1) and you still need 0.3A for the heater in each one, so 2x the filament supply. Good luck!

[sluckey]

In reviewing your PDF documenting your Bandmaster and Trem-O-Nator circuit, I noticed that the layout calls for a 250k linear Intensity pot, but the schematic shows 50k (doesn't specify audio/log or linear). 10thTX's schematic posted earlier shows 50k, but his layout shows 50k-RA. Could you please clarify the correct value for this pot?

Haha. Probably some more errors between my schematic and layout. I'll make it a priority to try to fix those this weekend.

My Band Master has a bit of history that explains the different value pots. When I got the amp it already had a turret board replacement and the 6G16 bias vary tremolo circuit had replaced the AB763 roach optocoupler circuit. But the original 50K-RA pot was used rather than the 250K pot used in the 6G16. One of the complaints with the amp was very weak tremolo. No wonder! Anyhow, when I fixed that and several other problems with the amp, I began drawing up the "as is" schematic, properly showing the correct 250K pot for the 6G16 bias vary tremolo. Got the amp fixed up, but that was about the time I was experimenting with the Trem-O-Nator. Since this Band Master was no longer a collectors amp, I decided this was the perfect platform to try the TON in a real amp. Couple days later I had it up and running and began cleaning up my document files. The TON went through a couple minor changes during this time. I had changed the pot to 250K (6G16 value) when I originally fixed the amp and then changed back to 50K-RA (AB763 value) for the TON. But I overlooked the fact that my new layout and schematic did not quite agree.

Bottom line... The INT pot in my Band Master with the Trem-O-Nator is the original 50K-RA from the original AB763 amp. My schematic is correct and I'll soon correct the layout. Thanks for spotting that!

[Colossal]

Bottom line... The INT pot in my Band Master with the Trem-O-Nator is the original 50K-RA from the original AB763 amp. My schematic is correct and I'll soon correct the layout. Thanks for spotting that!

Awesome, Steve, thanks a lot for the background and calling out the correct value! 50k-RA it is.

[sluckey]

Changes made to the pdf. Are you considering building the TON?

[Colossal]

Changes made to the pdf. Are you considering building the TON?

Yes, actually...was considering bolting it into a 18W normal channel format. Was thinking of just using a whole tube for it, parallel triodes.

[sluckey]

Was thinking of just using a whole tube for it, parallel triodes.

I've wondered about that. There's also a SS version by 2deaf using a MOSFET over on Hoffman's forum.