#102 Robben Ford Amp (High Plate Skyline)

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grtamp
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Re: #102 Robben Ford Amp

Post by grtamp »

Thank for posting new scheme , but if Ford's amp #102 is a non-Hrm ,

what amp is this?:
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KT66
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Re: #102 Robben Ford Amp

Post by KT66 »

I believe that schem is an update to one of the original forum schematics that was known as ODSHRM101 - not amp number 101 mind you, but 101 in the sense of like what you would call an introductory college course. I searched the forum and can't find it, so I'll post it here ( Don't remember who to credit with it or I would).
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Ryan

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KT66
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Re: #102 Robben Ford Amp

Post by KT66 »

It was pointed out to me that I had the diode in the LED indicator circuit backwards so I fixed the schematic and uploaded a new version.
Ryan

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http://Classictubeamps.com
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Structo
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Re: #102 Robben Ford Amp

Post by Structo »

Was the only change to the latest version of the layout just the removal of the center tap of the HT winding (Yel-Red)?
Tom

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talbany
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Re: #102 Robben Ford Amp

Post by talbany »

Tom
Yes so far this is the only change.(what else is there?) I suppose I could change the color of the wires to match. You would have to use that same transformer for this to actually matter. I did go back and check the schematic of #123 which also used a FWB rectifier as well and have it wired the same as 102

Tony
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aflynt
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Re: #102 Robben Ford Amp

Post by aflynt »

Here's a variation on the #102 layout that I created and used with my amp build. It works with the CE chassis and Showman / Twin transformers, uses the precision power supply, adds a LNFB switch and incorporates a treble reduction network on the switching jacks of the loop. Hopefully it will be helpful to other people building these amps.

http://ampgarage.com/forum/download/file.php?id=23252

-Aaron
groovtubin
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Re: #102 Robben Ford Amp

Post by groovtubin »

aflynt wrote:Here's a variation on the #102 layout that I created and used with my amp build. It works with the CE chassis and Showman / Twin transformers, uses the precision power supply, adds a LNFB switch and incorporates a treble reduction network on the switching jacks of the loop. Hopefully it will be helpful to other people building these amps.

http://ampgarage.com/forum/download/file.php?id=23252

-Aaron
I`ve modified a Fender HR Deluxe for a guy in your neck o`woods! Pls forgive for putting this in wrong forum!

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aflynt
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Re: #102 Robben Ford Amp

Post by aflynt »

groovtubin wrote:
aflynt wrote:Here's a variation on the #102 layout that I created and used with my amp build. It works with the CE chassis and Showman / Twin transformers, uses the precision power supply, adds a LNFB switch and incorporates a treble reduction network on the switching jacks of the loop. Hopefully it will be helpful to other people building these amps.

http://ampgarage.com/forum/download/file.php?id=23252

-Aaron
I`ve modified a Fender HR Deluxe for a guy in your neck o`woods! Pls forgive for putting this in wrong forum!

jim@Omegaamps.com
Just saw this. Very cool. I think the D'Style amps are finally beginning to catch on around here a bit. As far as I know, no local stores are carrying anything like them yet though.

-Aaron
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JazzGuitarGimp
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Re: #102 Robben Ford Amp

Post by JazzGuitarGimp »

Hi All,

Is there an "expected voltages" chart for this amp? If not, can someone tell me what the five B+ node voltages are?

Many thanks,
Lou
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jelle
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Re: #102 Robben Ford Amp

Post by jelle »

Hi There!

For those of you that are into the Robben Ford tone and ODS....Picture of what appears to be Robben Ford's Overdrive Special. This picture was placed in the public domain, and subsequently shared with me. Since it was in the public domain already, I would like to add it here for future reference.

Looking at the picture, I see nothing out of the ordinary: One piece chassis, LNFB on V1B, separate relay transformer, Twin OT (?). It looks pretty typical for an amp of that era.

The interesting parts: nice two deck ceramic rotary switch for input voltage select, and the amp appears to have been partially recapped at some point with Illinois Caps, TAD (?) and Ruby/Magic parts. But the cap can was left in there, my guess is that it was doubled up to 2x 20uf.

I feel it is time to update the layout.

Have fun!

PS: Mods, would it be possible to please clean up this thread a bit? This is part of the 'Files' section, but has the appearance of a 'Discussion' thread, which it should not have. Thanks!
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bluesfendermanblues
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Re: #102 Robben Ford Amp

Post by bluesfendermanblues »

jelle wrote:Hi There!

For those of you that are into the Robben Ford tone and ODS....Picture of what appears to be Robben Ford's Overdrive Special. This picture was placed in the public domain, and subsequently shared with me. Since it was in the public domain already, I would like to add it here for future reference.

Looking at the picture, I see nothing out of the ordinary: One piece chassis, LNFB on V1B, separate relay transformer, Twin OT (?). It looks pretty typical for an amp of that era.

The interesting parts: nice two deck ceramic rotary switch for input voltage select, and the amp appears to have been partially recapped at some point with Illinois Caps, TAD (?) and Ruby/Magic parts. But the cap can was left in there, my guess is that it was doubled up to 2x 20uf.

I feel it is time to update the layout.

Have fun!

PS: Mods, would it be possible to please clean up this thread a bit? This is part of the 'Files' section, but has the appearance of a 'Discussion' thread, which it should not have. Thanks!
That's it??

Wow, after chasing the Grail for so long.....it's kind of an anticlimax to see the amp 'for real', but I really appreciate that you di post it, thanks Jelle!

What changes, besides power supply, do you think should be made to the layout posted by Tony?

I don't know what goop Dumble used back in the 80's, but are we absolutely sure, that amp was upgraded to a High Plate, Skyliner at all? If that's the original Goop, it could still be a low plate with Classic stack? Do we really know for sure, that it was 'upgraded'?
Diva or not? - Respect for Mr. D's work....)
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Structo
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Re: #102 Robben Ford Amp

Post by Structo »

Thanks Jelle!

Too bad the preamp is gooped.

Would have loved to see the parts there.
Tom

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ChrisM
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Re: #102 Robben Ford Amp

Post by ChrisM »

Interesting, I've never seen a real Dumble with the non-reservoir PSU caps perpendicular to the reservoir caps.
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Colossal
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Re: #102 Robben Ford Amp

Post by Colossal »

ChrisM wrote:Interesting, I've never seen a real Dumble with the non-reservoir PSU caps perpendicular to the reservoir caps.
Indeed. I noticed that myself and wonder if that is a mod? Maybe the caps are paralleled and no longer in series? Can't see the balancing resistors to know. Thanks for posting that shot Jelle.
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jelle
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Re: #102 Robben Ford Amp

Post by jelle »

You are welcome.

Allright, now that we are turning this into a discussion section:
All proposed changes to the layout are in my previous post.

I have seen one other ODS with that power supply board configuration. There are no balancing resistors, other than for the mains caps. The huge dropper resistor looks to be a 2.7K
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