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Topic: Resurrecting a Fender Silverface Vibrosonic Chassis |
Michael Brebes
From:
Northridge CA
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Posted 19 Sep 2017 10:09 am |
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I picked up this Vibrosonic chassis on eBay. It was cheap and I figured I could fix it back up and sell it, along with a 1x15" cabinet that I had built for a client who decided he didn't want it. It had most of the pots in place (which I partially removed before taking the pictures) and figured that the cost wouldn't be too high, until I found that even the pots were bad and all needed to be replaced.
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Michael Brebes
Instrument/amp/ pickup repair
MSA D10 Classic/Rickenbacher B6/
Dickerson MOTS/Dobro D32 Hawaiian/
Goldtone Paul Beard Reso
Mesa Boogie Studio Pre/Hafler 3000
RP1/MPX100 |
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Michael Brebes
From:
Northridge CA
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Posted 19 Sep 2017 10:21 am
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Replaced all the pots, all the electrolytic caps, most tone caps, missing power cord, missing power light, missing transformers with US made ones, missing knobs, missing tube sockets. Fixed all the missing wiring. Modified to Blackface style bias adjust. Modified for Reverb and Vibrato on both channels. Modified to remove overdrive circuit on Master Volume and to make MV to have no tone change throughout its range. Since they cost the same, I installed an output transformer that had 4, 8, and 16 ohm taps and installed a selector switch on the back of the chassis. Installed a complete new set of tubes and preamp tube covers. I don't think I forgot anything.
Now on to finishing the head cabinet to go with the 1x15" cabinet.
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Michael Brebes
Instrument/amp/ pickup repair
MSA D10 Classic/Rickenbacher B6/
Dickerson MOTS/Dobro D32 Hawaiian/
Goldtone Paul Beard Reso
Mesa Boogie Studio Pre/Hafler 3000
RP1/MPX100 |
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Michael Brebes
From:
Northridge CA
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Posted 19 Sep 2017 1:00 pm
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The shell for the Vibrosonic head is made and is just under the width of the cabinet. The speaker cabinet was originally made for a Dual Showman Reverb head. The piggy back screws were inside the head cabinet so the inserts on the speaker cabinet were made to align with those. I did a cutout on the bottom of the head cabinet so that I can reverse mount the clip bars so they go inward and there is just enough room to tie them in without them sticking out the sides of the head cabinet. Holes are drilled for the straps and the handle on top. Next is blocks for mounting the front panel and the rear panel. The reverb pan will need to mount to the front panel, like on the Silverface Dual Showman Reverb head.
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Michael Brebes
Instrument/amp/ pickup repair
MSA D10 Classic/Rickenbacher B6/
Dickerson MOTS/Dobro D32 Hawaiian/
Goldtone Paul Beard Reso
Mesa Boogie Studio Pre/Hafler 3000
RP1/MPX100 |
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Bill A. Moore
From:
Silver City, New Mexico, USA
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Posted 19 Sep 2017 1:25 pm
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Thanks for posting this!
I am in the process of building a Bassman for my wife, but will build a tone ring cab for the JBL. I intended to dish out the area on the bottom for handle clearance, but your idea makes more sense. I do want to use the tie downs, and tilt back legs, (and I don't have a tank to deal with!) |
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Jon Light (deceased)
From:
Saugerties, NY
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Posted 19 Sep 2017 2:12 pm
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I just had some service done on my SF DSR. There were some noise issues. My tech pointed out places where the fibre board was so warped that it was bottoming out. Among the things he did, he installed spacers and standoffs to compensate for this warpage.
I mention this just because that old rig you've got there has likely seen some warp-inducing conditions.
Nothing like seeing an old tank being brought back to the living. |
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Chris Boyd
From:
Leonia,N.J./Charlestown,R.I.
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Jim Sliff
From:
Lawndale California, USA
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Posted 19 Sep 2017 9:51 pm
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Is that an old-type bias cap? It does not look like any new ones I'm familiar with. If so - get it out of there. Same is true iif you happened to use old filter caps - they can't be reformed safely and are time bombs - can blow with absolutely no warning.
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No chops, but great tone
1930's/40's Rickenbacher/Rickenbacker 6&8 string lap steels
1921 Weissenborn Style 2; Hilo&Schireson hollownecks
Appalachian, Regal & Dobro squarenecks
1959 Fender 400 9+2 B6;1960's Fender 800 3+3+2; 1948 Fender Dual-8 Professional |
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Michael Brebes
From:
Northridge CA
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Posted 20 Sep 2017 6:53 am
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All new electrolytics so no "timebombs" in the amp. Most of the Fender amps actually have a secondary fiber board underneath the eyelet board, which keeps the connections from grounding out to the chassis even if the board is warped. I actually worked for Fender in their R&D department back in the 80's so am very familiar with their assembly practices.
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Michael Brebes
Instrument/amp/ pickup repair
MSA D10 Classic/Rickenbacher B6/
Dickerson MOTS/Dobro D32 Hawaiian/
Goldtone Paul Beard Reso
Mesa Boogie Studio Pre/Hafler 3000
RP1/MPX100 |
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Jim Sliff
From:
Lawndale California, USA
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Posted 20 Sep 2017 11:34 am
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| Quote: |
| Most of the Fender amps actually have a secondary fiber board underneath the eyelet board |
I'm very familiar with Fender's amps, circuit bards, parts, circuit versions etc - I'm working on one almost every day.
I was simply asking about caps as the bias cap you installed *looks* like a vintage NOS or pull - It's a unusual size and color for a new one and can't be clearly identified.
Some less-expereinced folks that rebuild vintage amps buy old caps at hamfests and such thinking "NOS parts will be a great idea!" - when they're not.
Just mentioning it (and the filter caps) in case it *was* an old part and you didn't know not to use them.
IMO it's better to mention it and find out it's new & the owner is experienced than not mention it and have a newbie's amp blow.
_________________
No chops, but great tone
1930's/40's Rickenbacher/Rickenbacker 6&8 string lap steels
1921 Weissenborn Style 2; Hilo&Schireson hollownecks
Appalachian, Regal & Dobro squarenecks
1959 Fender 400 9+2 B6;1960's Fender 800 3+3+2; 1948 Fender Dual-8 Professional |
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Doug Earnest
From:
Branson, MO USA
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Posted 20 Sep 2017 8:31 pm
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| Would you mind to provide a cost estimate of the electronics parts used for this project? |
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Mark Fowler
From:
Minnesota, USA
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Posted 21 Sep 2017 5:09 am
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I rebuild junked out amps all the time so I think it is great to upcycle this old chassis, congrats.
Cost around $600 to $800 in components plus cabinet from my experience but I have a large inventory of parts.
Mark |
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Godfrey Arthur
From:
3rd Rock
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Posted 21 Sep 2017 5:09 am
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| Michael Brebes wrote: |
| Since they cost the same, I installed an output transformer that had 4, 8, and 16 ohm taps and installed a selector switch on the back of the chassis. |
What brand transformer did you use?
_________________
ShoBud The Pro 1
YES it's my REAL NAME!
Ezekiel 33:7 |
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Michael Brebes
From:
Northridge CA
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Posted 21 Sep 2017 9:00 am
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Jim - the capacitor you are questioning is a capacitor that I have had in my stock for a while. I think it is Cornell Dubilier or some brand like that. I am not a believer in NOS electrolytic capacitors.
Doug - the full set of transformers was $200. Tubes were another $100. 12 pots, 12 knobs, 4 1/4" Switchcraft jacks, 4 Switchcraft RCA's which should come to another $100. Piggyback hardware $75. Four ceramic octal sockets with tube clamps, two 9 pin sockets, 6 tube shields, pilot light socket and bulb, Fender capacitor board cover, orange drop capacitors, miscellaneous resistors, which should be another $100. New reverb tank and cables $30. Chassis straps $10. Wood, tolex, glue, handle, corners, and logo for cabinet is another $100. The speaker cabinet was another $60 in materials, with another $100 for a used JBL M151 that I had in stock. Amp rebuild with head cabinet comes in around $700 for parts and materials, and way too much in my labor. And don't forget the $150 I spent on the original chassis which brings the total cost to $850 (I will be giving away my labor when I sell this amp!). Speaker cabinet was about $160 in materials.
Godfrey - the transformers are made by ClassicTone. I have used their transformers before in repairs and builds and they are very good quality.
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Michael Brebes
Instrument/amp/ pickup repair
MSA D10 Classic/Rickenbacher B6/
Dickerson MOTS/Dobro D32 Hawaiian/
Goldtone Paul Beard Reso
Mesa Boogie Studio Pre/Hafler 3000
RP1/MPX100 |
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Michael Butler
From:
California, USA
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Posted 21 Sep 2017 9:23 am
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michael: i find this very interesting as i just built a 5e3 clone from scratch, other than the cabinet that i purchased. i also used a mercury magnetics PT and also opted for a multi OT with 4, 8 and 16 ohms. turned out to be a great amp.
please post more as you go along.
thanks,
mikeB
play music!
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please see my Snakeskin's Virtual Music Museum below.
http://muscmp.wordpress.com/ |
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Doug Earnest
From:
Branson, MO USA
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Posted 21 Sep 2017 10:38 am
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Very nice work!
Thank you Michael and Mark for your replies concerning parts costs.
It's easy to see how even a fairly minor rebuild of a sick old tube amp can run up a $500 bill very quickly. Ya gotta love 'em!
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Doug Earnest
Manufacturer of Stage One & Encore pedal steel guitars
http://www.stageonesteelguitars.com
"Teach Your Children Well" |
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Godfrey Arthur
From:
3rd Rock
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Posted 21 Sep 2017 12:55 pm
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| Michael Brebes wrote: |
Godfrey - the transformers are made by ClassicTone. I have used their transformers before in repairs and builds and they are very good quality. |
Michael, yes we use them too in Hammond organs as well.
As an aside, one could have the original xformer rebuilt as the iron inside the transformer contributes to the original tone.
https://www.youtube.com/watch?v=LoVt49PAK0s
_________________
ShoBud The Pro 1
YES it's my REAL NAME!
Ezekiel 33:7
Last edited by Godfrey Arthur on 27 Sep 2017 10:54 pm; edited 1 time in total |
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Michael Brebes
From:
Northridge CA
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Posted 27 Sep 2017 4:13 pm
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Got the tolex on the cabinet and most of the hardware. Yes, that is drops of glue that you see on the cabinet. Once it dries I can roll it right off with my finger. Just wanted to get moving on the hardware. The attached picture shows the clip bars in place and screwed down through the hole cut in the bottom. Because the clip bars do not need to be moved during transport, I just screwed them down so they can't move and they should always stay aligned.
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Michael Brebes
Instrument/amp/ pickup repair
MSA D10 Classic/Rickenbacher B6/
Dickerson MOTS/Dobro D32 Hawaiian/
Goldtone Paul Beard Reso
Mesa Boogie Studio Pre/Hafler 3000
RP1/MPX100 |
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Michael Brebes
From:
Northridge CA
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Posted 29 Sep 2017 12:28 pm
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| Godfrey Arthur wrote: |
As an aside, one could have the original xformer rebuilt as the iron inside the transformer contributes to the original tone.
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That of course is IF I had the original transformers, which were gone when I got the chassis.
The head is all assembled with the grill, emblem, amp, etc. The only thing left is the little bar on the back to hold the power cord inside.
Next, a couple finishing touches to the speaker cabinet.
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Michael Brebes
Instrument/amp/ pickup repair
MSA D10 Classic/Rickenbacher B6/
Dickerson MOTS/Dobro D32 Hawaiian/
Goldtone Paul Beard Reso
Mesa Boogie Studio Pre/Hafler 3000
RP1/MPX100 |
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Michael Brebes
From:
Northridge CA
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Posted 29 Sep 2017 12:49 pm
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While I've got everyone's attention, could you help me out with your opinion on the back of the speaker cabinet.
My original client wanted me to drop the weight of the speaker cabinet as much as possible, so I made simple tolex covered boards on the bottom and top of the back of the cabinet. The speaker jack was mounted on the top one. To keep weight down I made them of 1/4" plywood. When the client saw them he thought they were kind of flimsy, but I reminded my client that he wanted the weight minimized and that I used plywood to help give them some strength. I also offered to remake them in 3/8" or 1/2" plywood. The client's response was that he no longer wanted the cabinet (I received no down-payment so I was stuck with the bill for materials).
Here are my choices:
1) I can leave them with the 1/4" plywood.
2) I can make them with 1/2" ply and in such a way that they would have a lip for screwing in another board to completely close the back of the cabinet.
3) I could just make a full size board and close off the back of the cabinet.
Any opinions?
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Michael Brebes
Instrument/amp/ pickup repair
MSA D10 Classic/Rickenbacher B6/
Dickerson MOTS/Dobro D32 Hawaiian/
Goldtone Paul Beard Reso
Mesa Boogie Studio Pre/Hafler 3000
RP1/MPX100 |
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Michael Butler
From:
California, USA
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Posted 29 Sep 2017 3:40 pm
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| Michael Brebes wrote: |
While I've got everyone's attention, could you help me out with your opinion on the back of the speaker cabinet.
My original client wanted me to drop the weight of the speaker cabinet as much as possible, so I made simple tolex covered boards on the bottom and top of the back of the cabinet. The speaker jack was mounted on the top one. To keep weight down I made them of 1/4" plywood. When the client saw them he thought they were kind of flimsy, but I reminded my client that he wanted the weight minimized and that I used plywood to help give them some strength. I also offered to remake them in 3/8" or 1/2" plywood. The client's response was that he no longer wanted the cabinet (I received no down-payment so I was stuck with the bill for materials).
Here are my choices:
1) I can leave them with the 1/4" plywood.
2) I can make them with 1/2" ply and in such a way that they would have a lip for screwing in another board to completely close the back of the cabinet.
3) I could just make a full size board and close off the back of the cabinet.
Any opinions? |
just in case the client doesn't want any of those choices, you may want to do what you think would sell it otherwise.
my opinion is #2 since it includes a way to close it completely.
good luck.
play music!
_________________
please see my Snakeskin's Virtual Music Museum below.
http://muscmp.wordpress.com/ |
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Godfrey Arthur
From:
3rd Rock
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Posted 29 Sep 2017 9:24 pm
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I'd go with #2. Makes for a ready solution for either treatment.
But depending on the grade and type of plywood used you could get away with thinner boards if you were using multi ply birch or phenolic ply.
Phenolic ply 12mm and 18mm. Used for boat repair and cement molds.
Water proof, gorilla proof although not necessarily lighter.
For backboard use, sturdy and stiff as plies come.
I built a Leslie speaker cabinet out of the above phenolic. The router bits to cut the louvers had to be replaced for going dull during cutting.
Something to do with the resin used in the ply oatmeal in addition to the type of wood.
I used 12mm for the 3 sides and top of the cabinet and 18mm for back board, horn and woofer shelves and floor.
The cabinet sounds great and will last for generations.
Stiff and dense was reason tour cabs made for the Grateful Dead back in the 60's were out of void free birch ply.
Made for a better sounding cab for loud applications.
But birch is not as weather proof unless it's treated.
Birch ply. Yes that's 2+ inches thick back there.
_________________
ShoBud The Pro 1
YES it's my REAL NAME!
Ezekiel 33:7 |
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Michael Brebes
From:
Northridge CA
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Posted 9 Oct 2017 8:52 am
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Well, I just looked at the For Sale section to find out what the Vibrosonic Reverb amps were going for and saw the last one was last month and going for $900 with a split cabinet! If I sold mine for that amount I would lose money on the parts/materials and get nothing whatsoever for the hours of labor I've spent resurrecting this beast. That's depressing!
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Michael Brebes
Instrument/amp/ pickup repair
MSA D10 Classic/Rickenbacher B6/
Dickerson MOTS/Dobro D32 Hawaiian/
Goldtone Paul Beard Reso
Mesa Boogie Studio Pre/Hafler 3000
RP1/MPX100 |
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Godfrey Arthur
From:
3rd Rock
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Posted 9 Oct 2017 8:56 pm
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| Michael Brebes wrote: |
| Well, I just looked at the For Sale section to find out what the Vibrosonic Reverb amps were going for and saw the last one was last month and going for $900 with a split cabinet! If I sold mine for that amount I would lose money on the parts/materials and get nothing whatsoever for the hours of labor I've spent resurrecting this beast. That's depressing! |
Well those are "as-is" units, yours are a total rebuild. Which is why guys like you would need to carve a mod guru niche for yourself, come up with a recognized mod style where someone who likes your sound and work would buy your product and pay you for your expertise.
Like Dumble and the others before you.
There are amp gurus for particular amps I'm sure you know.
Post sound demos of your work on Youtube and see where it goes.
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ShoBud The Pro 1
YES it's my REAL NAME!
Ezekiel 33:7 |
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Steven Paris
From:
Los Angeles
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Posted 10 Oct 2017 12:19 am
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Nice work so far!!
Just musing.....some interesting "improvements" to the original might be:
DC-elevated heater supply
Metal-film resistors in first preamp section
Larger choke and larger-value power supply capacitors
Let us know how she sounds!!
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Emmons & Peavey |
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Michael Brebes
From:
Northridge CA
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Posted 11 Oct 2017 6:39 pm
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Oh, the amp sounds great. More bottom with the 15" than a Twin with two normal 12's.
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Michael Brebes
Instrument/amp/ pickup repair
MSA D10 Classic/Rickenbacher B6/
Dickerson MOTS/Dobro D32 Hawaiian/
Goldtone Paul Beard Reso
Mesa Boogie Studio Pre/Hafler 3000
RP1/MPX100 |
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