Help Dating Silverface Bassman

[teleforumnoob]

I got my old head out of storage to get repaired. I know it needs tubes, and most likely caps as well.
Can yall help me identify it?
Serial # on back is A 61102, hard to see in pic but its here:

It has 67 printed in the lower right corner of the black backplate under the ext jack, and says 50 watts under the speaker jack :

The tube chart inside has no mnf stamp, but it says AB 165, I'm assuming thats the circuit design. Also in the lower right corner of the tube chart is printed 027948

Heres the front. Long tail Script, says just Bassman, not Bassman 50.

 

[bunny 7]

Looks like 1970. Check out this link and scroll down to "Fender Amp Chassis Serial Number Date Codes.

http://www.superiormusic.com/page195.htm

There's a chance of being a '76, but I had one like yours in 1969 so just saying Bassman makes me suspect the '70 date is close.

Transformer codes would give more info as to actual date for you within a few months or so. Hope it helps.

 

[teleforumnoob]

Thanks bunny7. I saw that chart, it says A60000 for 1970, so I figured maybe 71 or 72, Maybe that means A6XXXX is 1970?
But what about that little #67 on the back?

In any case when I get er runnin its gonna be sweet!

I got this thing in a trade 25 yrs ago and just left it at a friends house cause he had a cab and I didn't. He used it lightly off and on till 5-6 yrs ago when it finally crapped out completely.
I got it back today and am gonna get it repaired and use it at last!

 

[Wally]

Hre to learn everything you might need to know about dating vintage Fenders. http://www.superchamp.dk/papers/dating_fender_tube_amps.htm
Notes:
1) That is not an AB165 circuit despite the tube chart. That is going to be one of the 'newest' Bassman amps I have seen with a BF tube chart. That amp is likely a 1970 or 1971, adn it will be a '70- or '71 circuit.
2)Dating by the codes will tell you what to know. The codes will date the amp and establish originality of components at the same time. A 1970 Fender with non-original components----transformers, speakers, or wholesale replacement of board components and pots.....is not worth what an all-oriignal amp of the same age and cosmetic condition is worth, so ose particulars are really what you want to know, ime. I have seen too many 'vintage' Fenders in the last few years that were sold for much more than they were worth.

 

[teleforumnoob]

Thanks Wally. My instinct was 71 or 72 base on the ser #.
Its doubtful the thing has been tampered with. I got it on a multi instr trade back around 1986. Most likely I was prob the 3 rd owner. Guy was using it to power monitors, lol.
Left it at a friends house cause he had a cab and I didn't. He used it lightly and infrequently only in his bedroom till 6-7 yrs ago when it completely crapped out.
6L6s are GE made in USA.
If its not AB 165, then what is it and how do you tell?

I'll read up on your link, thanks.

 

[Wally]

noob, a tech has to take a look at the circuit to determine which circuit it is. Fender used tube charst unti lthey were gone...soemtimes even using the wrong model. I had a '68 Dual Showman with a AB165 bAssman chart in it. I had a '57 5E3 Deluxe with a chart that read '5F6A' (Bassman).

 

[teleforumnoob]

got my wifes little magnifying makup miror and its
606-1-11

From
(link removed)
DATING FENDER AMPLIFIERS (INCLUDING SILVERFACE AND BLACKFACE AMPS) USING TRANSFORMER CODES
In general, Fender amps that don’t have rubber-stamped tube sticker date codes have EIA numbers on their transformers that might enable determination of the production date. These numbers always begin with “EIA 606,” and are followed by three or four digits in various combinations.

If three digits are present, the first digit refers to the year (i.e., a “7” would mean 1967).


So it appears this one is a 71, poss November?
Seems like you were pretty close Wally!

 

[vibrasonic]

606-1-11 means the transformer was made on the 11th week of 1971 which means your amp was made a little after that date.

 

[teleforumnoob]

^ Thanks everybody !!

 

[Wally]

And...that tranny code would lead one to believe that the circuit is an AA371.....March of 1971....regardless of the tube chart.

Also, FWIW.....this statement from that fender,com quote...
"These numbers always begin with “EIA 606,” and are followed by three or four digits in various combinations."

is incorrect. The 'always begin with EIA 606' is the part that makes teh statemetn incorrect...regardless of the source. Once in a while there are transformers in these amps that come from a different manufacturer, and therefor their EIA code does not start with '606'.....but rather one will see
"854" in that code.

Noob, if you really want tog et intot he details of vintage Fenders, go to that l ink I gave you. Those 3 authors spent years compiling data from thousands of FEnder amp with the help of the community of players and techs that own and play vintage FEnder amps. They are the folks who are responsible for the dating charts whereby we can identify production years by the serial number. Before 1976, Fender amp serial numbers meant nothing at all because the compilation and correlation of the data had not been done to allow one to segment those serial numbers into specific years. FEnder did not compile serial number data as regards year of production until 1976. Tehwork done by Gagliano, Hyntington and Reigle(?) is THEdefininng resource for vintage FEnder amps....and is the source from which all other 'sources' draw their info regarding serial number dating.

 

[teleforumnoob]

Thanks everyone for their expertise.
Looks like what I've got is a 69-70 shell based on cosmetics(long tail logo, no drip edge, gold in weave, bassman only logo)
with a mid-late 71 AA371 circuit(based on transformer date and serial #)

If this is the case, would there be a particularly desirable mod for my purposes?
(guitar-tele and Gretch hollowbody, doubling as a low to moderate volume bass amp, P/J w flats)
A little breakup at 3-4 would be nice for guitar, but not absolutely necc if thats interferes with performance w bass, clean to 5-6 or so would be acceptable as I can always get dirt from a pedal.

I first plan on running it with an old Carvin 15 ext bass cab I already own.
If I'm unsatisfied with the guitar sound with that I can always put another cab together for guitar with different speakers for more breakup.

 

[Wally]

noob, does that cab have a removable grille panel that is secured to the baffleboard with Velcro tabs? IF so, you have a late '70-'71 cab with a glued-in baffleboard. IF that cab has aone-piece baffle/grille board that is secured to the cab with screws, then count yourself as lucky. I prefer the older one-piece baffle/grille board construction.
The Normal channel on these amps is fairly hot for guitar.....and can be made hotter. The Bass channel was voiced for just that...Bass. IF the amp has original electrolytics, then those need to be replaced...all of the filter caps, the bais cap/s, and hte bypass caps, imho. I always revert the bias circuit to a true voltage adjustment circuit. There are things that can be done to that amp, but imho it is a decent platform for guitar as it is. Hot rock and hot country work well there. OF course, as with any amp, you'll need to use a boost pedal with that Tele, ime. (;^) Gibson's can make that amp go to work without any assistance.

 

[teleforumnoob]

^ Thanks Wally, great info!
As far as the grill goes, no screws are visible looking at it head on.
I didn't try to pry it off.

 

[Wally]

Noob, the screws that I mentioned go through some cleats on the sides and at the bottom of the interior of the cab of the one-piece baffle/grilleboard amps. They are visible looking into the cab from the back. In late '70-early '71, this method was abandoned for the glued in baffleboard withthe Velcro-attached grille board. The cab with the glued-in baffleboard will not have the cleats or runners down the sides of the front of the inside of the amp....the baffleboard and the cab meet in dado joints without any cleats....the glued joint is visible in the inside of the cab.

 

[SamClemons]

I am running a 2-10 cabinet with bass speakers with a similar rig. Really like it. Can run bass or guitar through it, and size makes it portable.

 

[speedingjet]

Well, find something you both have in common, set up an activity based on that. If there's chemistry, there'll be another date.

 

[Wally]

Noob, the laugh is on me, right? I am thinking combo while you have a head without the speaker cab.

 

[teleforumnoob]

Noob, the laugh is on me, right? I am thinking combo while you have a head without the speaker cab.

My fault for using "cab" in an above post to describe the head enclosure.
I've since edited that word to "shell".

Wally,
Whats you take on impedence matching?
THis head has 2 outs, speaker, and ext speaker. I'm assuming both are 4 ohm.
I've always heard its ok to run 4 into 8 or 8 into 16, but not vice versa.
But there is someone on another board cautioning me about that, says is hard on the output transformer, do you agree?

 

[Wally]

Noob, i n stock form that isa 4 ohm head. FEnder provided for the mismatch at 2 ohms by providing a paralleled output....two 4 ohm loads in parallel yielding a 2 ohm load. Most folks feel that a vintage Fender will tolerate a mismatch in the other direction, also....up to a 100% mismatch at 8 ohms. I am not as comfortable moving in that direction.
And.....all amps sound and function best at a match. So, 4 ohms is beset for the amp. OF course, our fellow member jefrs is of the opionion that vintage FEnder OT's were actually built at half of the stated impedance...so 2 ohms for a 4 ohm rated OT like this one. IF one were to run an 8 ohm load on such an OT, then the chance of flyback voltage surely increases because the mismatch is 200%. I prefer to run vintage FEnders at the stated impedance....4 ohms for that amp.

 

[E5RSY]

Definitely one of the last years before the logo lost its tail and "50" was added to Bassman.