Ry Cooder's Borderline Special

[Bombacaototal]

Some info on the tremolo

It could be either VibroChamp cathode-bias-wobble trem
http://ampgarage.com/forum/viewtopic.ph ... it=tremolo

Or less likely a Fender Tremolux 5E9-A with a few changes (simlar to the schematic from this thread)
http://ampgarage.com/forum/viewtopic.ph ... ne#p231435

[Bombacaototal]

I wanted to revive this amp

I spent some time tracing this circuit based on the 3 gut shots I had and the schematic previously provided here

I used this website to track the resistor values: www.hobby-hour.com/electronics/resistorcalculator.php

I added in blue further info I managed to gather and spotted a few discrepancies: PI load is 100k/110k, the NFB is of a surprisingly different values than usual dumble ODS (2.7k / 270R or 470R)

I have question marks on some resistors which were too blurry to spot

I found interesting that most resistors are at 2%. Do most of you follow this? Mine are usually at 5%

Also interesting that the plate loads were 1/4W RN65C and not the usual RN65D 1/2W

One thing I never managed to understand is what is the use for the balance trimmer between the PI loads? http://ampgarage.com/forum/viewtopic.php?t=18048

Interestingly I found out this tremolo circuit is a Vibrolux 6G11 (schematic attached) which was the same assumption of 10thTX. I am not sure I managed to put the correct values at the correct places tho.

While tracing the amps my resistor and cap values for the tremolo were identical to Sergios one (handwriting on post above) although the wiring and schematic not the same

[Bombacaototal]

I found this link with lots of pics of this amp http://s197.photobucket.com/user/odourb ... sort=3&o=0

Audio reference: https://www.youtube.com/watch?v=EelWp1V ... re=related

And here the incomplete layout I found on TAG. What is he using the 2 extra spare power tubes for?

[sergio]

The Ry Cooder's tremolo comes from another brand of amp, not a Fender!!!
The schematic above is not correct!
S.

[Bombacaototal]

The Ry Cooder's tremolo comes from another brand of amp, not a Fender!!!
The schematic above is not correct!
S.

Thanks for the comment sergio. It had the same number of components and lots of values were similar to the vibrolux 6g11 which is why I thought it was the correct circuit. Is the correct one a magnatone?

[Bombacaototal]

I just came across the magnatone 260-A and I am thinking that maybe this is where this trem circuit is coming from?

[FuzzFaceBuilder]

Here's the Magnatone tremolo circuit.

Put in a 2M2 resistor in place of the 3M3, and adjust the value of the capacitors and pots, then it looks a lot like this.

[Bombacaototal]

Here's the Magnatone tremolo circuit.

Put in a 2M2 resistor in place of the 3M3, and adjust the value of the capacitors and pots, then it looks a lot like this

Thanks for sharing. Which magnatone circuit did you take this screenshot from?

I wonder if the tremolo on this song is either of his Dumbles or a Fender or another amp

https://youtu.be/31FrrSlQoxo

[FuzzFaceBuilder]

Here's the Magnatone tremolo circuit.

Put in a 2M2 resistor in place of the 3M3, and adjust the value of the capacitors and pots, then it looks a lot like this

Thanks for sharing. Which magnatone circuit did you take this screenshot from?

I wonder if the tremolo on this song is either of his Dumbles or a Fender or another amp

https://youtu.be/31FrrSlQoxo

Sure thing! It's from a Magnatone T-32 that was sold under the Estey brand name.

http://www.prowessamplifiers.com/schema ... o_amp.html

[Bombacaototal]

Thanks for the reference FuzzFace. I was just wondering if Dumble would use a 1/2 tube trem and leave the other half unused. It sounds uncharacteristic of him. Maybe it is the circuit you posted with some additions? I have to go through the gut shots and values again and see what might have been missing

I spent sometime yesterday going through some silvertone trems like the 1484 but does not seem to be the case

One thing is for sure, one of the trem pots is a 250k the other I could not tell

[martin manning]

Maybe the same as this one: http://ampgarage.com/forum/viewtopic.ph ... 21#p218521

[Bombacaototal]

Maybe the same as this one: http://ampgarage.com/forum/viewtopic.ph ... 21#p218521

Hi Martin, I actually was looking into the SSS#001 trem as well which is from the M10A. The thing that intrigued me is that the original uses 12DW7 and SSS which you kindly helped on seems to be a 12AX7 although the values look fairly similar

The values in the borderline seems a bit different tho, including the pot value, so I would think it comes from somewhere else

[martin manning]

Take a closer look at the M-10 schematic... the tube type is 12DW7.

[Bombacaototal]

Take a closer look at the M-10 schematic... the tube type is 12DW7.

The schematic I have of SSS#001 indicates 12AX7. Maybe I don't have the latest one?

The layout seems to indicate the 7025 tube

Do you have the correct one handy to share?

[martin manning]

Take a closer look at the M-10 schematic... the tube type is 12DW7.

M-10 vibrato schematic uses 12DW7, not SSS 001.