Today you choose.... FORD's or TAG's

[bluesfendermanblues]

Hey all,
Just wanted to jump in and confirm some things:
Enjoy

Hi Brandon,
Great to see you back on the forum and very kind of you to share info on Robbens amp.

BTW can you confirm the specs provided by Shad on TAGs #183 amp??

- EL34 High plate skyliner eq.
- No LNFB on V1
- 330uf's paralleled for the B+
- 250K Gain
- 25pf/1KV snubber....that is not a typo that is what is printed on the caps (250K) and was measured.
- 100K od trim set to 21.53 from ground.
- Bias was set to 30.3mA @ 465.5 DC plate voltage
- 1K5 screen resistors
- No bright caps.
- Pacific Iron, sold to New Sensor, resold to Ruby Tubes, sold to Dumble.
- Typical Marshall output, Twin power, twin choke.

[dogears]

Brandon only has the pics and what was described by Shad.

I can say that based on the discrepancy between RFs OD trimmer measurements with amp on versus off (Shad saw 10% lower reading), seems that Tags amp may have been set at 23.5-24K on. Or set it off at the 21.5k. I have a working clone of it and it prefers the 24K range. For my taste.

Amp sounds spectacular btw. I believe these values are correct. Not too bright either (although I used 33pf snubs on the OD). I had 270pf prior and although great, it was more dynamic with the lower value.

Please note that 183 has a 30% taper 250K treble pot and a 250K linear! midrange pot. I have played the amp and it is not short on mids!! I wondered about it and then saw the pic!

Hey all,
Just wanted to jump in and confirm some things:
Enjoy

Hi Brandon,
Great to see you back on the forum and very kind of you to share info on Robbens amp.

BTW can you confirm the specs provided by Shad on TAGs #183 amp??

- EL34 High plate skyliner eq.
- No LNFB on V1
- 330uf's paralleled for the B+
- 250K Gain
- 25pf/1KV snubber....that is not a typo that is what is printed on the caps (250K) and was measured.
- 100K od trim set to 21.53 from ground.
- Bias was set to 30.3mA @ 465.5 DC plate voltage
- 1K5 screen resistors
- No bright caps.
- Pacific Iron, sold to New Sensor, resold to Ruby Tubes, sold to Dumble.
- Typical Marshall output, Twin power, twin choke.

[mlp-mx6]

What is a "Sprague Q-line resistor"? Google apparently can't find anything like that.

BTW, thanks to all for the cool info!

[ChrisM]

Great to see new pics and old faces, thanks.

[Max]

Hey all,

Just wanted to jump in and confirm some things:

Since i was actually the one who was in Robbens Tan Dumble with the Green Light, ...

Hi Brandon,

Thanks for this clarification and the video links.

Now we have this contradiction:

In this video RF tells around 4:15 that he owns the green light amp with the green switches in the tan cab since 1982:

http://www.youtube.com/watch?v=nBw_M2cQyQ4

But as the picture posted by Brandon shows the inside of this "green light - green switches" amp, this cannot be from 1982. I have never heard of, or have seen myself or on pictures, such a "three part - wooden sides" chassis from the early eighties.

Has someone an explanation for this obvious contradiction?

Perhaps RF does not want to impart in this interview, that he has this Dumble (green light, green switches) since 1982 but - a Dumble?

But then, what does his first one look like? Is it this one with the Vox grill cloth:

http://www.youtube.com/watch?v=HvFsvmoUsnI

http://www.youtube.com/watch?v=AUbf8FOu2ek ?

And if so and this "Vox grill ODS" really should be his first ODS from 1982, does he still own and use it (and by this had perhaps at least four ODS amps at hand when he recorded "Politician"?)?

And is the "Vox grill ODS" then perhaps the one he used for the TTYD recording sessions?

Cheers,

Max

[Max]

What is a "Sprague Q-line resistor"? Google apparently can't find anything like that.

The "Sprague Q-line resistors" are the tan carbon film resistors he used in most of the transition generation and 4th generation amps - like #124 as an example.
Out of production and hard to find NOS.

Cheers,

Max

[talbany]

Brandon

Here's a pic of Tag's amp if there aren't any up already

But as the picture posted by Brandon shows the inside of this "green light - green switches" amp, this cannot be from 1982.

Max
The picture Brandon posted was #183.. Did you perhaps think it was the Ford amp..

Tony

[Structo]

Strange on the gut shot, that the bias feed resistors are 270K (at least that's what they look like). Red, Violet, Yellow
Or are they Red, Brown, Yellow? 210K?

And ditto on the PI plates. 100K and 120K?

Looks like a Xicon film cap on the output of the PI.

[Max]

Brandon

Here's a pic of Tag's amp if there aren't any up already

But as the picture posted by Brandon shows the inside of this "green light - green switches" amp, this cannot be from 1982.

Max
The picture Brandon posted was #183.. Did you perhaps think it was the Ford amp..

Tony

Yes, Tony, I misunderstood Brandon's post. Thanks for the clarification.

Then Brandon's post answers my question of course:

The technical specs of "the RF amp" given here in this thread, are those of the "green switches - green light" ODS that now resides in the tan head cabinet ("Amp 1" in my post). Did I get it right now?

But then still there is the question: What is known about this "Vox grill amp"?

Thanks again and all the best,

Max

[ampdork]

Since i was actually the one who was in Robbens Tan Dumble with the Green Light, and Shad's Values are out of one of my "Ojai Special" amps that he took it upon himself to "incorrectly" alter:

Well it is the classic dumble trip innit?

If Dumble was keeping his clients happy you'd have never gotten "the green light".

Likewise had you not blown this one clients issues off then I would have never been given the "green light" either.

As for "incorrect". Sure if all one can do is paint by numbers and only do what Dumble did....then sure I guess it is "wrong".

If, however, one bases success on the client being happy then I think I succeeded where you did not....all for the cost of a pot...

Really you have no one to blame but yourself. Had you taken proper care of your clients concerns they would have never come to me with them.

I get it that your Ojai is a clone of a Dumble amp....and I get it that it may be dead on with the real thing.... and I can understand some measure of frustration with clients whom feel the amp did not make them into Ford...
But it's at that point one must realize that these people are not seeking the actual clone amp....what they seek is their own notion of what that should be like....and I guess that could cause some frustration when your unsure what would make them happy moving forward...

And so it was that I "fixed" your issue with this client via a pot.

So I dunno man....maybe next time be willing and able to venture of the pasture dumble plowed and learn to work with your clients instead of putting all the eggs into the "Well dumble did it this way" basket.

BTW does the real amp really use 15% audio taper Alpha's as were in the clone?

I am thinking no.....so I guess you also "incorrectly" changed pot tapers in this amp?

Looks like, according to your definition of "incorrect", you've made 4-5 "incorrect" changes versus my one...

But in any event it is great to see you sharing further details openly.

[ampdork]

Sprague Q-line NOS:
[img:640:480]http://img840.imageshack.us/img840/6390/dsc02677j.jpg[/img]

More Q-line:
[img:640:480]http://img830.imageshack.us/img830/2732/dsc02671b.jpg[/img]

Mepco/electra: The pretty blue ones:
[img]http:640:480]http://img97.imageshack.us/img97/8729/dsc02672so.jpg[/img]

The lower wattage version of these were used as grid resistors in the Ford clone I saw.

Piher, Beyschlag, and Iskra's:


Various Di-Films and other tid bits:

[talbany]

T

he technical specs of "the RF amp" given here in this thread, are those of the "green switches - green light" ODS that now resides in the tan head cabinet ("Amp 1" in my post). Did I get it right now?

I believe so Yes!

We know the green light amp resided in the Black head during the early 90's and used this one during the end of the Blue line years before Tiger Walk era..Where he he may have taken delivery on the gold script model and used that one more often than the green light one .. He then went back to the green light amp after the tan head switch and started using it again around 2002 time frame..The question here is is the green light amp the same as what was in the suede cab W/vox grill cloth or was this a completely different amp..Anybody!!.. Also does anyone know the serial on the green light amp?

Tony

[dogears]

Shad, Brandon ordered over 1000 30% taper pots in the sizes needed. As far as I know, the Ojai amps use the correct tapers. RF had 30%. My Ojai has 30%, as do all the ones I am aware of. Are you sure that the one you checked out had 15%?

Since i was actually the one who was in Robbens Tan Dumble with the Green Light, and Shad's Values are out of one of my "Ojai Special" amps that he took it upon himself to "incorrectly" alter:

BTW does the real amp really use 15% audio taper Alpha's as were in the clone?

I am thinking no.....so I guess you also "incorrectly" changed pot tapers in this amp?

Looks like, according to your definition of "incorrect", you've made 4-5 "incorrect" changes versus my one...

But in any event it is great to see you sharing further details openly.

[bluesfendermanblues]

Brandon only has the pics and what was described by Shad.
Please note that 183 has a 30% taper 250K treble pot and a 250K linear! midrange pot.

Ok, So Shad changed the 250KB middle pot (in Brandon's picture) to a 250K lin. ....

[ChrisM]

Looks like a Xicon film cap on the output of the PI.

DC blocking cap for the PI. No signal passes through, not a big deal it's Xcion. HAD has used these before there (also on post PI coupling).