DeArmond R5 amp review - schematic??

[moonbird]

Hi All -

For years I have heard about the DeArmond R5 amp and how great they are -- but goodness they are pricey.    There is (supposidly) one on EBAY right now:

http://cgi.ebay.com/Tube-Amp-Martin-112-T-like-DeArmond-R5T-/190554124034?pt=LH_DefaultDomain_0&hash=item2c5de92f02

Has anyone here ever played one? Have any clips?? How are they different?? Is it the iron or the circuit?? Does anyone have a schematic??

I have to admit to being a real DeArmond pickup nut - I have vintage DeArmond pups (and reissues) in several guitars I own. Despite their hum issues (I use a wrist strap to cut the hum <grin> on my acoustic pub ala Les Paul from the "Paul and Mary" days ) I just love how they sound and respond to the nuances of guitar playing.

Thus -- I would really like to try a R5.

Any suggestions on similar designs??? thx.

[Willabe]

For years I have heard about the DeArmond R5 amp and how great they are -- but goodness they are pricey.    
Thus -- I would really like to try a R5.
Any suggestions on similar designs??? thx.

I'm pretty sure the guys at Tone Quest Magazine loved that amp and did a story on it. I think they also cloned it, and had M.M. do re-makes on the transformer set and had someone make 25-50? of them to sell.

Call them or e-mail them, copies of past issues are $5? Their nice guys and I'm sure they'll help you out.

Let us know what you find out.


         Brad        

[Willabe]

OK, I went back through my back issues and found Feb. 2006/VOL.7,  NO.4 p. 19.

Tone Quest Report (not magazine) did clone one, but without the trem. Mercury Magnetics cloned the transformer set, but they beefed them up to be able to also use 6L6's with a 5AR4  --   "for slightly more power and a bigger attitude." 


One of their tube tech guy's (Jeff Bakos, Bakos AmpWorks) was (is?) making them, but what's the fun in that? $2 grand. They're calling it the " Clarksdale". Comes with Sozo caps and a 12" Eminence Wizard speaker. They have a punched chassis, maybe they'ed sell you one? I'd bet you can get the tranny's from M.M. , if you wanted too?

They say in here they reviewed it a couple of times before this issue , but I can't seem to find those.     

Hope this helps you moonbird.


            Brad         

[VMS]

This thread has a schematic and instructions for the tremolo model R5T:

http://www.letstalkguild.com/phpBB2/viewtopic.php?f=9&t=4441&start=45

[moonbird]

Holy Moly VMS -

Thanks very much -- now you say that Mercury Mag made some trafos for the R5T? Great I will drop them a line and report back!!

[VMS]

I did some more searching and the link I gave you shows that the R5T is a single-ended amp and probably equivalent to Martin 110.

The ebay link shows a Martin 112t which is a push-pull amp. Maybe deArmond equivalent for that amp is R15T 

Here's a schematic I found for Martin 112t:

[VMS]

...and here's the ToneQuest article that Willabe mentioned:

http://www.tonequest.com/content/newsletter_details.asp?ArticleID=2

[Willabe]

The scheme I see is for the SE 5w? amp, not the PP 20w?

The seller on ebay listed it as the Martin 112 model/ DeArmond R5T, with 5Y3, 2- 6V6's, 3- 12_ _ 7's. Schemo shows 6X4, 1-6V6, 2- 12_ _7. 2 different models. There's also an R25T, 2- 6L6's, 2x10 with trem, 25w?

I'm not sure a SE 5w amp is what you want for acoustic pub ala Les Paul? No head room.    

AFAICT, the Martin amps were re-branded DeArmond amps made by Rowe Industries in Toledo, Ohio.

TQR cloned the 2- 6V6 model, no trem. I found the old issues, they said bare bones circuit and -- huge -- OT! Aug. 2004/Vol.5 No. 10.


          Brad            

[moonbird]

VMS --

Must say that thread you directed me too is very interesting (and funny). If there are others out there interested in these obscurities -- it is highly recommended!! 

[Willabe]

Well, it looks like a 5E3 Tweed Deluxe. Interactive volume controls, you can bridge the 2 channels or use an A/B box for clean and over drive. Same driver, PI, and PP OP stage, with no FB loop.

Here's the link to the 5E3 in Doug's library. Print them both out and study them side by side. Same circuit, with a few different parts values. Martin has trem option on some models, not on all their amps. Looks like if you copy the Martin schemo parts values and just use a bigger OT you'll likely nail it?      

http://www.el34world.com/charts/Schematics/files/fender/deluxe_5e3_schem.pdf


TQR did not  say (reveal?) any of this except that the OT was "huge". Not really any thing to hide, no secrets here.    


         Brad      

[VMS]

I found a youtube clip for the SE amp:

C.F. Martin 1x10 amplifier like Dearmond...with Les Paul

and for the Push-Pull amp:

Dearmond R15T amplifier with Les Paul...C.F. Martin


That guy also has clips with strat.

[worth]

Anyone have a scheme where V1B isn't conveniently smudged ?

[moonbird]

Worth --

Good question - is a bit of a drag 

[sluckey]

Here it is cleaned up. Ain't no mojo in this circuit.

http://home.comcast.net/~seluckey/dearmondschematictx1.gif

Get it now if you want it. It'll be gone Friday.

[DummyLoad]

the tone pot is an odd value - parallel a 1M w/ 1M8 resistor to get ~650K.

don't wire up the filaments as shown in the original schematic.

--DL

ignore my schematic - thanks slucky. :-)

[DummyLoad]

Here it is cleaned up. Ain't no mojo in this circuit.

sshhh! it's the 650K pot! Z

[sluckey]

sshhh! it's the 650K pot! Z

Yes! That's it! I spent so much time removing the clutter around the tube that I totally overlooked the tone pot. That's obviously the soul of that amp. Can't believe I missed that! The copy cats will never be able to capture the sound.... 'til some ebay guru starts dribbling out rusty 650K pots one at a time.   

[John]

starts dribbling out rusty 650K pots

That's spelled "vintage".

[moonbird]

Seems like its all in the high quality components and the BIG iron!! Anyone have suggestions for oversized iron to make the SE amp?? Biggest SE OT I know of is the MPS 20watt SE. It has a 2.5.k tap that could be doubled with a mis-matched speaker. Is it strickly a weight thing? Bigger the better?? Are there other SE OTs out there to try? I am pretty sure the Mercury Mag stuff is going to come back more expensive than I will wanna go.

Others speculate that maybe the R5T has got an oversize PP OT that is big enough not to be saturated despite the lack of an air gap?? Maybe the PS connects to the centertap as usual but both plate wires run to the single power tube. Would that double or cut the impedence in half?? Sounds gooky. Does that make sense to anybody?

Thanks again for all the input.

[moonbird]

Here is a monster OT from Edcore -- $83

http://www.edcorusa.com/products/473-cxse25-4-5k.aspx

[VMS]

Classictone has 15W versions of the champ iron. And the price ain't bad either.

http://www.classictone.net/Fender-Style-Transformers.html#anchor_1749

[worth]

The DeArmond R-T15 and the Martin 112-T are obviously the same amp. Someone should draw up a layout from the schematic.

[sluckey]

Someone should draw up a layout from the schematic.

Why not give it a go? There's a link to free software on the board. It's easier than you may think. Drawing your own layouts is an excellant way to become intimate with a schematic.

[moonbird]

VMS --that ClassicTone iron looks perfect!! THANKS!! I will get it on order!!

Sluckey -- thats a great idea -- I will do it. Would you suggest a turretboard or point to point?

What software do you recommend?? I have Visio but have no amp component shapes. Is there a better way? thx.

[moonbird]

Just heard back from MercMag - they have PP OTs only and a 327-o-327 PT. I posted the info on the Dearmond 15T thread if anyone is interested ...

[sluckey]

What software do you recommend?? I have Visio but have no amp component shapes. Is there a better way? thx.

I was speaking of PC Express. I use Visio. You can download my shapes from my website. If you're proficient with Visio, it'll be a snap. If not, there will be a steeper learning curve that PC Express. The results are well worth the effort.

[moonbird]

You can download my shapes from my website.

sluckey --

Your Visio shapes are terrific -- I am off and running. Thanks kindly!! Will post my attempts for critique and suggestions.