Help with Negative Feedback connection Super Reverb

[Fender Guy]

Please see picture attached. Loose wire is on top around 12 o'clock. It has black heat shrink on tip

Some one told me it appears I have a Negative Feedback Loop disconnected on my Blackface Super Reverb (the disconnected wire pictured).

I have not been able to google where it goes.

Hints here and there of connection of loose wire should go to speaker jack, but if that is the case do I solder wire speaker jack or ext. speaker jack, and to ground or positive connection?

Hope you can help..Thanks

[ToneMerc]

See schematic........ext jack via main spk output, hot side.

TM

[xtian]

Schematics: http://www.ampwares.com/amp.asp?id=97

[Fender Guy]

See schematic........ext jack via main spk output, hot side.

Sorry to say, I do not know how to read a schematic.

Can you explain "ext jack via main spk output, hot side"

I understand ground or hot, but not ext jack via main speaker output?

So..do I solder hot side of ext speaker jack, or hot side of main speaker jack hot side.

Can someone put posted picture in paint or something and just draw a circle where I need to solder it???

No need to give me the speech about high voltages..I know it can kill you.

Thanks for the fast response guy

[Fender Guy]

BTW The amp sounds REAL good. I may like it better the way it is, but would like to try it with the Negative Feedback Loop connected "just to hear the difference".

Some say they like the loop as better clean, some say they like the negative feedback loop disconnected (more dirt).

I only play at home so I use a TS9 for distorted sounds any way.

For the life of me, I am not sure the amp can sound any better but I am curious what the difference will be. The loop has been disconnected since I bought it back in the 80's. I just realized it is disconnected.

[ToneMerc]

See schematic........ext jack via main spk output, hot side.

Sorry to say, I do not know how to read a schematic.

Can you explain "ext jack via main spk output, hot side"

I understand ground or hot, but not ext jack via main speaker output?

So..do I solder hot side of ext speaker jack, or hot side of main speaker jack hot side.

Can someone put posted picture in paint or something and just draw a circle where I need to solder it???

No need to give me the speech about high voltages..I know it can kill you.

Thanks for the fast response guy

The NFB circuit is connected to the ext jack, which in turn is connected to the main speaker jack, the hot side. It looks like to me that the "taped" tail is already connected to that jack. You have 2 options, a new continous wire from the main board to that jack or either connect that tail to the wire originating from the main board.

See layout.........ext jack area, a wire from it to an 820 ohm resistor on the main board.

TM

[Bob-I]

Yes, the connection directly below the loose wire is the proper connection point.

[Ian444]

I'm not sure, but to me it looks like the taped wire IS the wire coming from the 820 ohm resistor. Can you trace that wire back? Is it connected to the extension speaker jack or the circuit board? Photos can be tricky to work from...If that taped off wire runs to the circuit board (goes in between the 2 blue caps) I would think that the far left terminal of the far left speaker jack in your photo would be the place to reconnect it.

Edit - missed your post Bob, yep, what you said.

[Randy Magee]

If you look really closely, the taped wire is already connected to the tagboard... it has just been disconnected from the extension speaker jack, taped and looped around the other yellow wire. Just solder the taped wire to the terminal that the yellow wire is attached to on the extension speaker jack or you might even put it on a switch so you can have it with or without negative feedback.

[Fender Guy]

Thanks for the response guys.

Randy, great directions.

Any one here heard a super reverb with and with out the feed back loop, can you describe the difference in sound if you can, and what you prefer.

I have always had the amp this way as when I bought it the amp already had a solid state rectifier and this feed back loop disconnected. I did hear a friends BF super reverb. His had a tube rectifier and it just sounded better then mine to me. That could have been from the tube rectifier, the feedback loop, or maybe even something else.

Thanks guys

[Randy Magee]

Thanks for the response guys.

Randy, great directions.

Any one here heard a super reverb with and with out the feed back loop, can you describe the difference in sound if you can, and what you prefer.

It will be much cleaner sounding with NFB loop... when you d/c the NFB, the amp gets a little bit louder and more raw sounding...

I have always had the amp this way as when I bought it the amp already had a solid state rectifier and this feed back loop disconnected. I did hear a friends BF super reverb. His had a tube rectifier and it just sounded better then mine to me. That could have been from the tube rectifier, the feedback loop, or maybe even something else.

I kind of like the bit of sag a rectifier introduces... I'd expect the voltages might go up a bit using a solid state rectifier as well.

Thanks guys

[Fender Guy]

Randy, your description sounds pretty much what I have read.

Have you heard a SR with and with out the loop?

I had a silverface SR (two volume knobs), that was a cleaner, more sparkly sounding amp. A cleaner sound seems like it would sound like the silverface SR?

I will have to try it that is for sure. I have it put back together but will pull it apart soon.

Thanks

[Randy Magee]

Randy, your description sounds pretty much what I have read.

Have you heard a SR with and with out the loop?

I haven't heard a SR in particular without NFB, but I've played with the NFB on my old '66 Bandmaster...

I had a silverface SR (two volume knobs), that was a cleaner, more sparkly sounding amp. A cleaner sound seems like it would sound like the silverface SR?

I will have to try it that is for sure. I have it put back together but will pull it apart soon.

Thanks

[Fender Guy]

Well there does seem to be a difference in tone.

The amp seems more quiet for one thing. I was having trouble with reverb howl when turning reverb up past 7. Now I can turn reverb all the way up to 10 and no howl. There is a slight hum in reverb setting at 10, but when backed off to 9 hum goes away too.

I like the amp with the feedback loop connected but am considering a switch mod or maybe even the mod where you remove the ext. speaker jack and slip in a pot for full adjustment.

I like the amp with and with out the negative feedback loop!

[Teleguy61]

Welcome to tweaker madness.