help with my twin reverb

[Tom Phillips]

EDIT: I have inserted several edits below to correct the information I provided during the first post. This will help prevent confusion if someone reads this post in isolation at a later time.

...choke-A #022921 and next to it 11A606-034

That part was manufactured during the 34^th week of 1970. [Edit: or 1980. Actually the -034 part of the code indicates the first year of a decade. Which decade is determined by other factors concerning the part and the equipment in which it is installed. Also the part number #022921 is not a choke. It is a reverb drive transformer.]

…013691 AND E1A606-034…

Date code also indicates manufactured during the 34^th week of 1970 [Edit or 1980...see above edit]

…main transformer- A013692 and E1A606-139 ,and UL1411 stamped into metal…

Based on all that I’d say manufactured during the 39^th week of 1971. [Edit or 1980...see above edit] Unless it has been replaced then the amp had to have been manufactured no earlier than [Edit: September 1981.]

…...the tech and the guitar store both believe this is a early 60's amp???
I guess at this point it doesn't matter since it's mine anyway... …

I don’t agree with the tech or the store. I think it is an early 1970’s amp. [Edit: Most likely 1981 amp based on a re-review of the clues] However, I do agree that you still got a good deal well worth what you paid.

I forgot to ask what does pulling out the master volume knob suppose to do??? when I use this push/pull master volume switch it doesn't seem to make a difference in sound output..

Another dead giveaway that the amp is a 1970’s Silverface. Probably a Silverface amp that has had a blackface front panel installed on it. It’s also very common for people to mod Silverface amps to take out the pull boost function. A big confusing point, however, is the existence of a master volume control at all on a “Blackface” Twin Reverb. Is it actually marked “Master” with original silkscreened letters on the front panel? If you post photos of the amp, including a clear gut shot of the inside of the chassis it will answer a lot of questions. [Edit: Follow this thread for more information contributed by the members about the second issue blackface Twin Reverb amps produced from 1980 through 1982]

[Steve A.]

... when I try to send pic's to the music-electronics-forum.com it doesn't work??? there must be a email address I can send pic's to???

Option #1. If you have already uploaded your pic's to the web you can click on the picture icon that is 3rd from right on the edit tool bar. To display the picture full size and in-line with the text of your post unclick the button that says "retrieve remote file..."

Option #2. To attach a photo from your computer you first need to click on "Go Advanced" and scroll to the bottom to find the manage attachments section. (Let me know if you have trouble getting that to work- you need to click the right buttons...)

Steve Ahola

[potatofarmer]

Is there a wattage listed by the output jacks?

There was a brief run of SF-era Twins that came with (at first, optional) BF cosmetics.

[popoahi]

ok I'm glad to get some info although it wud have been better to hear it was like a 65'..

ok about the master switch - it does have "twin reverb" with the "R" in a circle screened on it next to the switch, and the jewel power light. there's a silver border around all this the switch, light, and the twin reverb..
this makes it look like almost a separate face plate,,, its the same like the silver line around the vibrato section a the normal section of face plate...

underneath the master volume section and the silver line it has in small print " master volume and fender musical company" in silver color, same silver color as the "twin reverb" in a cursive looking print next to the master volume control knob...

can you tell me what this push/pull master volume switch does??
and on what year was this feature was available?

I have tried to send photo's from my phone but it says invalid..... there must be like a email address that I can send photo's to??
I've tried sending to- music-electronics-forum.com/7/......and without the 7 but no go...

thanks,,popo

[popoahi]

not sure what you mean by output jacks?
there is this where the power chord goes into the chassis and the AC plug,,, says- 120V , 60HZ, 200watts...
there is also a yellow UL sticker with some numbers on it -listed 155j UL......

the only other output jacks are the reverb in/out jacks on the rear plate.... and the front 4 output jacks which has no wattage numbers near them...

the tube schematic says "fullerton" did they make silverface amps there too???

I'm going to try to re-read the numbers off those transformers tomorrow with better lighting....

thanks, popo

[überfuzz]

I skimmed through this thread... Your amp, do you like how it sounds?

[popoahi]

yes I'm very happy with the sound so it doesn't matter much what year it is..
although to know if I ever sell it or just curiosity is great.
I wouldn't want to tell someone who I sell it to that it's a BF when it's not... but i dont think I will sell it so,,
my kids would have to
deal with that...

aloha, popo

[potatofarmer]

not sure what you mean by output jacks?
there is this where the power chord goes into the chassis and the AC plug,,, says- 120V , 60HZ, 200watts...
there is also a yellow UL sticker with some numbers on it -listed 155j UL......

Sorry, I meant the jacks where the speakers plug in. There were some 135W Twin Reverbs made between 81-82 with blackface cosmetics and they would say "135W" right beneath the speaker jacks. They would also say something like "350W" where yours says 200W so it sounds like you're in the clear!

[Chuck H]

I don't know enough about EIA codes to say if the system was any different WRT decade. I've read that the decade code is non specific. I don't know that there is any way to be certain that the codes given above, identified by Tom Phillips as being from 1970 and 1971, may actually be 1980 and 1981. This would correspond perfectly with the presence of a black face plate and master volume on the same amp. In 1982-ish Fender had a short lived series of black faced amps with silver faced appointments. Your description of the faceplate cosmetics also corresponds with this series of amps. I think your amp is likely a 1982 model. There was indeed a "Twin Reverb" amp in that line that didn't sport any extras to the name like "II" or "135". It would have simply said "Twin Reverb" on the face plate with the moniker in it's own delineated box on a black face plate.

[Enzo]

That is why you also look on the controls and other larger components too.

[potatofarmer]

I don't know enough about EIA codes to say if the system was any different WRT decade. I've read that the decade code is non specific. I don't know that there is any way to be certain that the codes given above, identified by Tom Phillips as being from 1970 and 1971, may actually be 1980 and 1981. This would correspond perfectly with the presence of a black face plate and master volume on the same amp. In 1982-ish Fender had a short lived series of black faced amps with silver faced appointments. Your description of the faceplate cosmetics also corresponds with this series of amps. I think your amp is likely a 1982 model. There was indeed a "Twin Reverb" amp in that line that didn't sport any extras to the name like "II" or "135". It would have simply said "Twin Reverb" on the face plate with the moniker in it's own delineated box on a black face plate.

Yeah, and these say "135W" under the output jacks. Unless the back plate was replaced, which would be odd.

The other thing that caught my attention was the mention of a "choke" but not a reverb transformer. If there aren't 4 transformers...

Pictures could solve this rather quickly. I'm no Fender aficionado but I think the master was added around 72 and the pull boost on the master was added around 74. The description of the faceplate is odd though; it could be a replacement on an otherwise normal mid-70s silverface.

[Tom Phillips]

I don't know enough about EIA codes to say if the system was any different WRT decade. I've read that the decade code is non specific. I don't know that there is any way to be certain that the codes given above, identified by Tom Phillips as being from 1970 and 1971, may actually be 1980 and 1981. This would correspond perfectly with the presence of a black face plate and master volume on the same amp...

Good theory. The transformer part numbers changed over the years too. Maybe we can narrow down the decade using those part numbers. I'll check my records. The master volume comment really threw a pineapple in the discussion. It tells me that the people telling popoahi that his amp was an "early '60s Blackface" are sorely lacking in the appropriate knowledge. That's the nicest way I can comment on that.

popoahi - Photos would really help clear this up. Maybe you should start a thread in the fun with computers forum specifically about how to get photos from your phone to attachments in your posts.

[Chuck H]

The OT part # does seem to identify it as the ultra linear, 135W twin. I don't think there's any need for confusion about the cosmetics and I don't believe it's a replacement face plate because I don't know of any replacement black face-face plates that include a spot for a master volume control, don't have an added part to the name and have "Twin Reverb" by itself in a box. Fender only made amps with these cosmetics for a year (maybe less). I suppose they are rare in that regard. I don't think it adds to their collectability though since it wasn't a popular line. Otherwise CBS wouldn't have discontinued these cosmetics.

FWIW the 135W Twin Reverbs are reported, by todays players, to be very good amps. I don't expect it'll be overdriven much, but that's why we have stomp boxes! Popoahi shouldn't be wanting for clean headroom any time soon.

[Steve A.]

In 1982-ish Fender had a short lived series of black faced amps with silver faced appointments. Your description of the faceplate cosmetics also corresponds with this series of amps. I think your amp is likely a 1982 model. There was indeed a "Twin Reverb" amp in that line that didn't sport any extras to the name like "II" or "135". It would have simply said "Twin Reverb" on the face plate with the moniker in it's own delineated box on a black face plate.

Well they do say that the 80s are the new 60s- right?

Steve

[Leo_Gnardo]

I don't believe it's a replacement face plate because I don't know of any replacement black face-face plates that include a spot for a master volume control, don't have an added part to the name and have "Twin Reverb" by itself in a box. Fender only made amps with these cosmetics for a year (maybe less). I suppose they are rare in that regard. I don't think it adds to their collectability though since it wasn't a popular line. Otherwise CBS wouldn't have discontinued these cosmetics.

True that & now it jogs my memory to a "reissue" BF made either '74 or '84. 10th or 20th anniversary model. I worked on one somewhere in mid 90's. My easily researched (computerized) records don't go back that far but some brain cells do. Also note the OT has no 022889 stamped into the cover - the standard Twin output until Fender went for a tapped-primary OT.