It is currently Mon Mar 16, 2020 1:08 pm

All times are UTC - 7 hours



Post new topic Reply to topic  [ 16 posts ]  Go to page 1, 2  Next
Go to page 1, 2  Next
Author Message
Post subject: Need some info on a Bassman 10 amp
Posted: Sat Sep 12, 2015 2:58 pm
Offline
Hobbyist
Hobbyist

Joined: Thu Jan 27, 2011 6:32 pm
Posts: 10
Just got the silverface amp from a pawn shop - it looks to have been used and abused in every smokey jukejoint in the midwest for the past forty years. This will be my winter project.
I'm trying to date it and have had no luck with online searches. I know they were made from 72 to early 80s, but would like to narrow that down.
There looks to be a serial # "A 00064" stamped on the back chassis, as well as a stenciled name " I Schults".
The transformer has 2 lines of digits on it - "021848" above "606-2-03"
I put fresh tubes into it, and it plays - but it doesn't seem to put out the volume I'd expect from a 50 watt tube amp. Also, after a good warmup period I cranked it and am not getting any breakup or distortion.
Any help with dating and service suggestions would be greatly appreciated.

Larry Kindel


Top
Profile
Fender Play Winter Sale 2020
Post subject: Re: Need some info on a Bassman 10 amp
Posted: Sat Sep 12, 2015 4:09 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Wed Mar 31, 2010 12:48 am
Posts: 26417
Location: Tombstone Territory
The "606-2-03" indicates that the transformer was made in the third week of 1972. If the other iron is similarly marked, then that gives you an idea of when this amp was built. Low output even with fresh bottles would tell me that there may be a power-supply issue, specifically the B+ voltage. My troubleshooting efforts would begin there and I would start by inspection the electrolytic caps in the filter array and also in the bias-supply circuit. Replace as necessary then check the power-rail resistors for indications of thermal abuse. Replace as needed (metal-oxide types will outlast the original carbon-comp resistors several times over). Any dead diodes in the rectifier circuit should also be replaced and in truth, it's probably wiser to replace them all if any of them measure as marginal. You might also check the speakers to ensure that they're wired correctly and all operating. IIRC they are 32Ω drivers, wired in parallel for a total system load of eight ohms. Don't neglect the routine procedures like cleaning the pots, switches, and jacks with a good contact cleaner such as Caig's De-Oxit and inspecting the chassis for any broken or fractured solder joints. Take a look at the 470-ohm screen-grid resistors across the power-tubes sockets -- if they look tired, replace (again, metal-oxide types will outperform the original carbon-comps).

Arjay

_________________
"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


Top
Profile
Post subject: Re: Need some info on a Bassman 10 amp
Posted: Sat Sep 12, 2015 8:07 pm
Offline
Hobbyist
Hobbyist

Joined: Thu Jan 27, 2011 6:32 pm
Posts: 10
Thank you for the reply Arjay.
I will be pulling the chassis this week to dig into the components.
A previous owner replaced the 4x10 speakers with a single 15" - and this meters out to 8ohm. As I said, it's been used and abused.
Plan is to go back to 4x10 - thinking maybe Celestion vintage ten 30s. I like mostly 70's rock and urban blues, so thought these would be a good choice.

Larry


Top
Profile
Post subject: Re: Need some info on a Bassman 10 amp
Posted: Sun Sep 13, 2015 2:38 am
Online
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14049
Location: Province de Québec, Canada
This is your amp ;

http://ampwares.com/amplifiers/fender-s ... assman-10/

1- Check AC fuse to be sure it is the right one to not damage your amp .

2- You should read all the power supply voltages first .This will tell you if you need to replace resistor or filter caps or rectifier diodes.
If voltages are good , you don't need to replace resistor or filter caps .
If you gig with the amp outside your home you may want fresh filter caps . Not for a home use .

Read the resistors in the phase inverter circuit , the tube just before outputs tubes .
Wrong value may drop power .

Show us some pictures from inside the amp to see any mods or burns parts

Tubes 's amp have lethal voltage and can kill you


Top
Profile
Post subject: Re: Need some info on a Bassman 10 amp
Posted: Sun Sep 13, 2015 7:11 am
Offline
Professional Musician
Professional Musician
User avatar

Joined: Tue Jul 17, 2007 3:08 pm
Posts: 2889
Here is my thread from earlier this year that deals with the Bassman 10 I restored, little tidbits of stuff i ran into along the way

viewtopic.php?f=12&t=98989

_________________
Keepn' the Blues Alive

2004 50th Ann. Limited edition AMSE Stratocaster
2017 50's Baja Telecaster BSB

1968 Bandmaster with 2X12 cab C-rex speakers
VHT Special 6 Ultra combo

Visual Sound Route 66
Cmatmods Signa Drive


Top
Profile
Post subject: Re: Need some info on a Bassman 10 amp
Posted: Thu Sep 17, 2015 1:05 pm
Offline
Hobbyist
Hobbyist

Joined: Thu Jan 27, 2011 6:32 pm
Posts: 10
I disassembled the amp today. Am awaiting an order of tolex, grill cloth and assorted cosmetic pieces to begin the cabinet rebuild.
The chassis doesn't look too bad, but it's going to my tech tomorrow for for eval and component replacements as needed. I have some pics but - being an infrequent forum user - do not know how to post them here.
The assembler's name ( J. Castillo) is stamped on the inside as well as Feb 4 1972 - so I guess that answers the dating question.


Top
Profile
Post subject: Re: Need some info on a Bassman 10 amp
Posted: Thu Sep 17, 2015 1:12 pm
Offline
Professional Musician
Professional Musician
User avatar

Joined: Tue Jul 17, 2007 3:08 pm
Posts: 2889
I use photobucket.com
They host the pictures and provide links to use on forums like this one

_________________
Keepn' the Blues Alive

2004 50th Ann. Limited edition AMSE Stratocaster
2017 50's Baja Telecaster BSB

1968 Bandmaster with 2X12 cab C-rex speakers
VHT Special 6 Ultra combo

Visual Sound Route 66
Cmatmods Signa Drive


Top
Profile
Post subject: Re: Need some info on a Bassman 10 amp
Posted: Thu Sep 17, 2015 3:06 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Wed Mar 31, 2010 12:48 am
Posts: 26417
Location: Tombstone Territory
lkindel wrote:
The assembler's name ( J. Castillo) is stamped on the inside as well as Feb 4 1972 - so I guess that answers the dating question.


I believe I may have mentioned that.

:wink:

Good luck with the cosmetic restoration -- holler if you need help.

Arjay

_________________
"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


Top
Profile
Post subject: Re: Need some info on a Bassman 10 amp
Posted: Thu Sep 17, 2015 3:35 pm
Offline
Hobbyist
Hobbyist

Joined: Thu Jan 27, 2011 6:32 pm
Posts: 10
Yes you did Arjay - information overload on my part, I guess.
Here's my first try at posting pics:
Image
Image


Top
Profile
Post subject: Re: Need some info on a Bassman 10 amp
Posted: Thu Sep 17, 2015 4:36 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Wed Mar 31, 2010 12:48 am
Posts: 26417
Location: Tombstone Territory
Seems to be unmolested and relatively clean......

Arjay

_________________
"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


Top
Profile
Post subject: Re: Need some info on a Bassman 10 amp
Posted: Sat Sep 19, 2015 7:34 pm
Offline
Hobbyist
Hobbyist

Joined: Thu Jan 27, 2011 6:32 pm
Posts: 10
Have the chassis at the shop - at first look my tech thinks it looks pretty good too.
Got my tolex and grill cloth in from Amplified parts today. Plan on spending some time in the woodshop repairing the cab and prepping it for recover.
A previous owner ripped out the 4x10 baffle board and kludged in a 15" radio shack speaker on a piece of cheap plywood. I'm thinking of replacing it with four Celestion ten 30s on birch plywood - any thoughts on those speakers in this amp.

Larry


Top
Profile
Post subject: Re: Need some info on a Bassman 10 amp
Posted: Sat Sep 19, 2015 7:38 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Wed Mar 31, 2010 12:48 am
Posts: 26417
Location: Tombstone Territory
How is the current replacement baffle board attached to the cab shell?

Arjay

_________________
"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


Top
Profile
Post subject: Re: Need some info on a Bassman 10 amp
Posted: Sat Sep 19, 2015 8:13 pm
Offline
Hobbyist
Hobbyist

Joined: Thu Jan 27, 2011 6:32 pm
Posts: 10
The original was ripped out of the cab - I guess they cut it into pieces and pulled the chunks free of the rabbit. The 15" board was screwed in from the sides with four 2" wood screws.
Amazing but true - the cab is still structurally sound.
I'll probably install cleats over and behind the orig rabbit so I can attach the new baffle board back to the correct position.


Top
Profile
Post subject: Re: Need some info on a Bassman 10 amp
Posted: Sat Sep 19, 2015 8:33 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Wed Mar 31, 2010 12:48 am
Posts: 26417
Location: Tombstone Territory
A proper set of interior cleats would be the preferred method of attaching a new baffle board. The cleats should be positioned 1" back from the front edge of the case, and firmly affixed (I prefer using both glue and screws as added insurance). Void-free ½" birch ply is an excellent choice for the board itself. You'll need a grill frame around the perimeter of the board -- I use ¼" poplar strip, along with a piece of ¼" poplar plank for the logo shelf. The end result should resemble this......

Image

Plan for the type of speaker fasteners and the number per speaker before stapling the grill cloth on.

Arjay

_________________
"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


Top
Profile
Post subject: Re: Need some info on a Bassman 10 amp
Posted: Sun Sep 20, 2015 8:21 am
Offline
Hobbyist
Hobbyist

Joined: Thu Jan 27, 2011 6:32 pm
Posts: 10
Thanks arjay - good info.
I still have the original grill frame and logo, which are a little rough but salvageable.


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 16 posts ]  Go to page 1, 2  Next
Go to page 1, 2  Next

All times are UTC - 7 hours

Fender Play Winter Sale 2020

Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to: