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

[ampdork]

No pictures.

Only discussions regarding circuits will be entertained.

Morality and ethics do not affect tone so we won't be talking them.

Now which one will it be?

[Structo]

I would pick Robben's amp.

But, Tag does know tone and I value his opinion.

[Mac Daddy]

The only way you can make that decision is by hearing and playing them first hand
With that said , Its a no brainer for me TKT

[tele caster]

Yup, Knows tone tag.

[wjdunham]

First, it would help to get a refresher on what the two circuits are: there's been a lot of speculation on Robben's amp and I can't quite piece together what it really is: HRM low plate skyliner? 6L6 or EL34, with a choke? From what I can gather about TAG's amp, it's a high plate skyliner EL34 with some obviously secret tweaks. A more complete description of each would help.
As far as the tone goes, to me apples and oranges. Luckily, I like both apples AND oranges. To ME: TAG's amp is very smooth, lush and fat, slightly darker, blooms like a mother, Robbens amp crisp, bright, fuzzless overdrive. Could be as much due to playing style as the amp itself. Interesting topic non-the-less, but would be more interesting with the photos to go along
Bill

[UltraHookedOnPhonix]

Personally, I find #183 a bit more interesting since it’s been loosely established that the RF amp is:

Skyline EQ
220K/150K plate resistors for clean and OD
3.3K/2.2K cathode resistors for clean and OD
4.7uF cathode bypass caps on all stages
Standard Overdrive (non HRM)
Does not have separate masters
PS Dropping string: 3K, 22K, 2.2K
PI plate resistors: 110K/120K with 10K trimmer
PI plate couplers: .1uF
Twin PT
Twin Choke
Twin OT

Of course, I’m sure the RF amp has plenty more tricks up it’s sleeves in coupler values, OD entrance, bright caps, OD snubbers etc. I’m still more intrigued by #183 though.

“Knowns” on #183:

Marshall Plexi OT
Twin PT
No LNFB on V1
Skyliner EQ
EL34’s
three-way bright switch
half-power switch

[Mac Daddy]

183 I believe has standard plate voltage w/both a Marshall & Fender tranny , Skyliner voicing

[IMG:800:450]http://i15.photobucket.com/albums/a373/ ... /41031.jpg[/img]

[IMG:799:473]http://i15.photobucket.com/albums/a373/ ... lerear.jpg[/img]

[Mac Daddy]

183 Pardon the crappy playing

http://www.youtube.com/watch?v=UJ4jgfiqdMw

[dr. who]

Any Dumbles had their cap values tested by a capacitance bridge? Why are the cap's exact values overlooked by so many people? I'm interested in both amps, but the RF seems to have more known about it circuit wise. I guess whoever was in the RF amp must give out a few more hints to HELP this community. I'll probably never try and build one of those circuits as I have other amps that have the tone I'm looking for(SSS, Classic w/ 6l6, OD w/ Ripper) and I can PM for that info as I am not an Amp Company lurking for "secrets".

[dogears]

I have played both Robben's amp and Tag's amp. Robben's amp has far more bloom. Bloomiest amp I ever played in fact. It is also not overly bright or crisp. I prefer RFs by a margin.

Tag's is quite nice though.

First, it would help to get a refresher on what the two circuits are: there's been a lot of speculation on Robben's amp and I can't quite piece together what it really is: HRM low plate skyliner? 6L6 or EL34, with a choke? From what I can gather about TAG's amp, it's a high plate skyliner EL34 with some obviously secret tweaks. A more complete description of each would help.
As far as the tone goes, to me apples and oranges. Luckily, I like both apples AND oranges. To ME: TAG's amp is very smooth, lush and fat, slightly darker, blooms like a mother, Robbens amp crisp, bright, fuzzless overdrive. Could be as much due to playing style as the amp itself. Interesting topic non-the-less, but would be more interesting with the photos to go along
Bill

[wjdunham]

I'm only going from the clips posted here of TAG's amp and RF recordings, I've not seen him live (TAG nor Ford). Interesting to hear a first-hand comparison of both amps. Scott, what do you suppose is are the big contributing factors to the bloom of Robben's amp, tube selection, coupling caps, voltages, magic?
Bill

I have played both Robben's amp and Tag's amp. Robben's amp has far more bloom. Bloomiest amp I ever played in fact. It is also not overly bright or crisp. I prefer RFs by a margin.

Tag's is quite nice though.

First, it would help to get a refresher on what the two circuits are: there's been a lot of speculation on Robben's amp and I can't quite piece together what it really is: HRM low plate skyliner? 6L6 or EL34, with a choke? From what I can gather about TAG's amp, it's a high plate skyliner EL34 with some obviously secret tweaks. A more complete description of each would help.
As far as the tone goes, to me apples and oranges. Luckily, I like both apples AND oranges. To ME: TAG's amp is very smooth, lush and fat, slightly darker, blooms like a mother, Robbens amp crisp, bright, fuzzless overdrive. Could be as much due to playing style as the amp itself. Interesting topic non-the-less, but would be more interesting with the photos to go along
Bill

[ampdork]

TKT amp:

el-34 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.

Iron was made by Pacific, sold to New Sensor, resold to Ruby Tubes, sold to Dumble.

Typical Marshall output, Twin power, twin choke.

Ta-da?

Ford amp:

6l6 high plate skyliner eq

LNFB on v1

220uf paralleled for B+
40Uf-50uf caps on V1+2

Presence is 2.2uF

24K tail

100K gain and Level pots. Linear was used in the amp I repaired... but to my ears a real 30% taper or even a common 15% audio works better for me. Mileage may vary....

Dropping string 2k2, 22k, 2k2

100K/110K PI

Mica caps for bright and for the mid boost

100K trim 23.44 from ground

33k input grid resistor V1

68pf bright cap

trying not to put my own opinion into the mix.... but do have to say that I think without the loop the Ford amp is by far a very bright amp.
Also the only "problem" I can see is that the damn thing wants to take every single note, ball it up and make it eat its own harmonic ass on the way to the moon.
They just take off.... learning to get a note to ring out without it taking off is way trickier then the other way around!
That takes some getting used to...

Any Dumbles had their cap values tested by a capacitance bridge? Why are the cap's exact values overlooked by so many people? I'm interested in both amps, but the RF seems to have more known about it circuit wise. I guess whoever was in the RF amp must give out a few more hints to HELP this community. I'll probably never try and build one of those circuits as I have other amps that have the tone I'm looking for(SSS, Classic w/ 6l6, OD w/ Ripper) and I can PM for that info as I am not an Amp Company lurking for "secrets".

Tag's was. Not going to dig up those notes though. Not overlooked though.
I must have missed the Ford stuff being posted here. ;O)
Sorry if this does not seem helpful to you....I KNOW there are others who will find it helpful...
Very cool you can get your amps built up via PM information but many, including non builders, cannot.... So I guess this thread if for those guys and not you.

I believe in free information for all. Not bartering. I shared this info because I can say I worked hard to get it on my own...
I have other information I am not sharing because I got it from others who do not agree with my views in sharing... Which sucks but that is the way it goes I guess...
Hopefully someday I will find other avenues of that same information and can then share it...


evolution beats wallowing in primordial ooze/secret sauces...

[dogears]

Thanks Shad!

Question, was the OD trimmer measured with the amp on and OD on?? The reading changes depending on whether the amp is on and OD engaged.....

Also, didn't 183 have some larger OD1 cap?? .05uf on OD1. Pretty important fact.

Thanks!

[Structo]

WOW!

Thanks a lot Shad!

Are you serious about 330uF paralleled for B+?

So 660uF total for plates?

Or did you mean series and 165uF total?

[johan]

Is this #183?

http://www.youtube.com/watch?v=Yj0QfWez ... re=related

Yummy!