NAD, and which circuit is in my Silverface 1972 Deluxe Reverb?

fretfinder

Does anyone know how to identify exactly which circuit is in a Silverface Deluxe Reverb. Mine is a 1972 model but there doesn't seem to be any number on the tube chart to indicate the circuit. From a bit of web searching it seems the circuit on an amp from that year could either be AB868, A1172 or A1270. It's a beautiful amp and sounds great whichever circuit is in it! Thanks in advance...

http://i1081.photobucket.com/albums/j359/Fretfinder/641abd15ef62be15318eb894b0c994bc.jpg

http://i1081.photobucket.com/albums/j359/Fretfinder/6faa62193e471fe2eac8bccb3ed7d2d7.jpg

RiftAmps

You need to post detailed photos of the chassis including internals, transformer codes, and any chassis markings that you can find. One of us will be able to indentify it from those.

ICBM

It won't be AB868 because that circuit was superceded in December 1970 (AA1270). If the amp was made before November '72 it will be AA1270, if it was made in December '72 it should be AA1172, although there were sometimes overruns. November is the only month which should be uncertain.

You can date the amp from the parts codes - which are on the transformer covers and the backs of the pots among other places. The transformers should have codes that read 606-2xx, where xx is the week of production, and the pots should have 137-2xx. The amp can't be any older than the youngest (original, obviously) part in it.

fretfinder

RiftAmps said:

You need to post detailed photos of the chassis including internals, transformer codes, and any chassis markings that you can find. One of us will be able to indentify it from those.

ICBM said:

It won't be AB868 because that circuit was superceded in December 1970 (AA1270). If the amp was made before November '72 it will be AA1270, if it was made in December '72 it should be AA1172, although there were sometimes overruns. November is the only month which should be uncertain.

You can date the amp from the parts codes - which are on the transformer covers and the backs of the pots among other places. The transformers should have codes that read 606-2xx, where xx is the week of production, and the pots should have 137-2xx. The amp can't be any older than the youngest (original, obviously) part in it.

Thanks for that guys. The transformer codes are 606205, 606150, 606-1-30, 606-0-22 so nothing later than May '72 so far. Not sure if I'll pull the tray out any time soon to check the pots but here's some gut shots I received from the previous owner.

http://i1081.photobucket.com/albums/j359/Fretfinder/F3E2CC69-8F99-4B23-BB32-A8E3BDC945E5.jpg

http://i1081.photobucket.com/albums/j359/Fretfinder/F67AA646-F448-459D-B387-1CDD0966EDF8.jpg

http://i1081.photobucket.com/albums/j359/Fretfinder/7C55AA00-1360-4A95-B83B-3F569C187E7A.jpg

http://i1081.photobucket.com/albums/j359/Fretfinder/C774E095-5478-4585-8E89-43D60F68A10D.jpg

ICBM

fretfinder said:

The transformer codes are 606205, 606150, 606-1-30, 606-0-22 so nothing later than May '72 so far.

That's nothing later than the 5th week of '72 - two are '71 and one is as old as 1970. Given that I think it's unlikely the amp was made any later than mid '72 at the latest.

DJH83004

It looks in very nice original condition from your photos, I think I can spot a cap has been added to reduce the trem tick, and may even be a new opto, but all sensible mods. Lovely amp 

ESchap

Were Fender using 1watt plate resistors in those days? or have those been upgraded? .. again sensibly.

equalsql

Just WOW! What a beauty. 

fretfinder

ICBM said:

fretfinder said:

The transformer codes are 606205, 606150, 606-1-30, 606-0-22 so nothing later than May '72 so far.

That's nothing later than the 5th week of '72 - two are '71 and one is as old as 1970. Given that I think it's unlikely the amp was made any later than mid '72 at the latest.

Thanks, dunno why I said May! Confusing week with month d'oh...

fretfinder

DJH83004 said:

It looks in very nice original condition from your photos, I think I can spot a cap has been added to reduce the trem tick, and may even be a new opto, but all sensible mods. Lovely amp 

Very well spotted! It is in very nice condition, with just a few essential changes, as far as I'm aware. You can just spot the bright cap mod, with one end unsoldered and wrapped in insulating tape.

ESchap said:

Were Fender using 1watt plate resistors in those days? or have those been upgraded? .. again sensibly.

I'm afraid I have no idea what '1watt plate resistors' means! I must read up more about these lovely amps...

IvisonGuitars

Looks a beauty Nigel, how does it sound?

fretfinder

miserneil said:

Looks a beauty Nigel, how does it sound?

It sounds lovely jubbly. I gigged it a week ago and it sounded great and it is also very loud, louder than the DRRI I had a while ago iirc. The speaker is a replacement Celestion G12H Anniversary which may partly account for the volume. The amp stays clean up to about 4 (which is frickin loud) and then gets progressively crunchy! I had a pedalboard issue three-quarters of the way through the gig, had to plug straight into the amp, turned it up a bit, used the guitar volume and it sounded lovely. Possibly even nicer than it had sounded through the cornucopia of ace pedals previously! I was playing this old fifties Junior thing I had lying around, that I picked up off some dodgy geezer early in the year... 

Wazmeister

Nigel, it's a beauty mate - congrats !

richardhomer

If there's ever been a better looking amp than a Deluxe Reverb, I've yet to see it.

I think it's highly likely I'll buy one eventually....

ICBM

The 1W plate resistors will be original, they did use them - I can't remember exactly when they changed. They're a better choice, the 1/2Ws are close to their limit.

colourofsound

That is a beaut. What's the noisefloor like on these? Much hiss at idle?

fandango

Call me jealous. Wouldn't mind one of these, but for the home it seems a bit overkill.

ICBM

fandango said:

Call me jealous. Wouldn't mind one of these, but for the home it seems a bit overkill.

I've never understood this thinking… they sound magical at even very low volume.

So does a Twin Reverb for that matter.

BBBlues

Great looking amp! When did the "drip edge" silverfaces finish, 69? 

IvisonGuitars

fretfinder said:

miserneil said:

Looks a beauty Nigel, how does it sound?

It sounds lovely jubbly. I gigged it a week ago and it sounded great and it is also very loud, louder than the DRRI I had a while ago iirc. The speaker is a replacement Celestion G12H Anniversary which may partly account for the volume. The amp stays clean up to about 4 (which is frickin loud) and then gets progressively crunchy! I had a pedalboard issue three-quarters of the way through the gig, had to plug straight into the amp, turned it up a bit, used the guitar volume and it sounded lovely. Possibly even nicer than it had sounded through the cornucopia of ace pedals previously! I was playing this old fifties Junior thing I had lying around, that I picked up off some dodgy geezer early in the year... 

That's no way to talk about poor old @Blacksheep!

Blacksheep

Those old p90s don't need much help.