newbie with a Bandmaster and no sound

ct_yankee · Newbie Alert Joined: 16 Jan 2007 Posts: 4

I recently came into possession of a '67 Fender Bandmaster (and a '64 Gibson ES-335) that has been sitting in a dusty warehouse for the last decade or so. I plugged in the speaker and turned on the Power and Standby switches, and the power tubes glow a nice warm orange (the four smaller ones have metal sleeves on them so I can't see if they're lit), but I can't get any sound. I'm trying to figure out another way to drive the speaker so I can rule that out, but I haven't done that yet (don't think that's the problem). I am completely out of my element as far as troubleshooting goes, so I have a few questions...

1. What is the function of the horizontal toggle switch labeled "Ground" on the back of the head?
2. What is the proper order of operation for turning on the amp? Plug in the speaker before powering on? "Power" and "Standby" both on? Should "Standby" be switched off to play?
3. What size bulb should be in the power indicator on the face of the amp (it's missing)?
4. What do the "Bright" slide switches do (there's one for the normal channel and one for the vibrato channel)?
5. Is the vibrato pedal just an on/off switch or a variable pedal, like a volume pedal or wah-wah? If it's just an on/off, can I use just any old normally open pushbutton switch?
6. Any idea where to find an owner's manual (if there is such a thing)?

Tube chart data:
Bandmaster-Amp AB763
Production 31
Power Supply 117V 50/60 cycles AC
Power Consumption 175W
Tubes - 6L6GC, 6L6GC, 12AT7, 12AX7, 7025, 7025
Date Code - QC

Thanks in advance for any help.
Tom
Glassy-eyed in CT Shocked

owwdatune · Posted: Tue Jan 16, 2007 11:40 am Post subject:

ahhhhh...sounds like a question for our own fender amp freak HERB....stay tuned ct yank.....i'm sure Herb will be by soon #Flash

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owwdatune · Posted: Tue Jan 16, 2007 11:49 am Post subject:

in the meanwhile...perhaps check this out >>>

http://www.ampwares.com/ffg/
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Herb · Posted: Tue Jan 16, 2007 5:24 pm Post subject:

Welcome to the forum! Very Happy

Here's what I can tell you:
1. Amp only has a 2 prong power chord, flipping ground switch will lift ground if amp is buzzing.
2. Always have speaker plugged in before turning anything on. First power switch up (on), then standby switch up when you're ready to play.
3. I'll have to look that up, but it's not necessary to operation.
4. "Bright" switches add high treble frequencies to "brighten" guitar tone when switched up.
5. Vibrato pedal switch is an SPST on/off switch, you don't even need another switch, just take an old RCA plug and bent the "-" lead lug on the back over the "+" lead on the back of the plug (shorting it out) and plug it into the socket for it in the back of the amp. The Vibrato will always be "on" then, and you can turn it off using the intensity knob on the front of the amp.
6. I have one for a '66 Bandmaster that I bought new back in '66 (same amp), but it's not leaving my possession. You might check at guitar shows or JK Lutherie.

Just so you know, date code QC - Q = 1967, C = March.

I also recommend that you try another speaker cord, I'm willing to bet that that one has set so long it is corroded and won't carry enough current to make the speakers work. Same with the guitar cord.
_________________
Yer guitar pickin' friend,
Herb
"It don't mean a thing if it ain't got that swing!"
Doghouse Jazz

ct_yankee · Newbie Alert Joined: 16 Jan 2007 Posts: 4

Owwdatune - thanks a lot. I have that site in my bookmarks already! Smile

Herb - Thanks for the info. I did give a light sand to the inside of all the input jacks, got a new speaker cable, and let her sit with the power on and standby off for a little bit. Then I plugged in my guitar, flipped the standby switch and ran through a little riff... holy cow, is this amp sweeeet! Very Happy

Awesome clean sound. Now I just have to clean 'er up. I read a post somewhere (I've read so many this week) by a guy who said he puts the knobs through the dishwasher. Ever thry that? I'll just soap & water the tolex and see what a shop vac will do for the grill cloth.

One other thing. In my quest to nail down the age, I've come across a bunch of photos of the '67 blackface mounted on a horizontal cabinet (mounting studs on a long side). My cabinet has the mounting studs on the short side (with the Fender logo positioned correctly), so it stands vertically with the head attached. Is this a different year cabinet (or for a different amp)? I haven't seen a photo of one like it anywhere. It has a metal tag attached under on of the feet that's stamped P09899 and F091567 is printed on the wood crossmember inside. It also has (1) Jensen C12PS speaker, while most info I can find says the Bandmasters came with C12N's. Any ideas?

Thanks in advance. And again, thanks for the help.
Tom

Herb · Posted: Thu Jan 18, 2007 4:02 pm Post subject:

You have the correct cabinet for '67, that was the year they changed from horizontal style to larger vertical style. Speaker variations were common for Fender at this time.
_________________
Yer guitar pickin' friend,
Herb
"It don't mean a thing if it ain't got that swing!"
Doghouse Jazz

ct_yankee · Newbie Alert Joined: 16 Jan 2007 Posts: 4

Thanks Herb. Would ther be any benefit to adding another speaker to the cabinet? Would it have to be the same model speaker (I guess that would be optimal)? Should it be connected in series or parallel with the first one?

Thanks in advance.
Tom

Herb · Posted: Fri Jan 19, 2007 4:44 pm Post subject:

I'm unclear as to how many speakers are in your cabinet. It should be a 2 x 12" cabinet, with 2 matching speakers wired in parallel.
_________________
Yer guitar pickin' friend,
Herb
"It don't mean a thing if it ain't got that swing!"
Doghouse Jazz

ct_yankee · Newbie Alert Joined: 16 Jan 2007 Posts: 4

The cabinet only has (1) Jensen C12PS speaker. Sad

Herb · Posted: Sat Jan 20, 2007 8:12 am Post subject:

The vertical '67 Bandmaster cabinet was a 2 x 12" speaker cabinet that measured 29 1/2" x 40". Speakers were mounted one above the other. I had to go back to "the book" to verify this. If yours is only a one speaker cab, it isn't a '67 Bandmaster cab. Got pics? Also, check the ohmage of your speaker, and then the ohmage of your output transformer. Your transformer should be a four ohm for two speakers. If your single speaker is either eight or sixteen ohms (especially if it's sixteen!), it's time to quit using it. If you have an eight ohm transformer for one speaker somehow (modification?) and an eight ohm speaker,or even a four ohm transformer and a four ohm speaker (rare), you're OK.
_________________
Yer guitar pickin' friend,
Herb
"It don't mean a thing if it ain't got that swing!"
Doghouse Jazz

roverjohn · Sea Monkey Joined: 11 Feb 2007 Posts: 14

I have to disagree with Herb here a bit assuming I'm reading his post correctly. The main point is that it NEVER causes a problem driving speakers of higher impedance than the rated tap on the output transformer. So, if your output trans is rated at 4 ohms and your single speaker is 16 ohms you will do no harm whatsoever to your amp. You will just get less power out which may or may not be the tone you want. So as long as the combined imnpedance of the speaker is equal to or greater than the rating on the output trans you are fine and will do no harm to your amp. People hace been driving 8ohm cabs of the 4ohm tap forever.
John...

ilovemacintosh · Not So Newbie Joined: 12 Feb 2007 Posts: 9

Replies in this post are really helpful.

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