[rajacat]

Here are some pics of my freshly refurbished Heathkit W5m monoblocks. These amps were rebuilt by a very knowledgeable friend and he replaced just about every original part except the transformers. The stock 12au7 tubes were changed to 6cg7's. The stock power supply caps were replaced but the old covers remain so the amps still look stock. They sound very smooth and linear with great extension. I'm using  Shuguang KT66 for the power tubes and have been rotating RCA 6C67's and Sylvania 6CG7's.

-Roy


 
Before rebuild



After:

[rajacat]

A sexier night image.

[Lyndon]

Thanks for the photos, Roy.  I would love to hear these little wonders.
A long time ago, when JohnR was residing in San Fran, I believe, he had a pair of
Eico monoblocks that were pretty nice.  I don't know if he still had them here or if they were only posted
over at Harmonic Discord.
I know I enjoy my Eico ST-40 in the bedroom setup.  Very good with female vocals, don't you think?
Lyndon
Salt Lake City

[EDS_]

Specfriggintacular!

[JoshK]

The iron in these babies is suppose to be primo.  I am jealous. 

[Listens2tubes]

  SWEET!

[ab0ez]

Roy, you're gonna make me blush!  I'm glad you're enjoying the amps.  Don't forget, we gotta get together so I can upgrade the dropping resistors in the power supply network.

Jim

[ZLS]

Here are some pics of my freshly refurbished Heathkit W5m monoblocks. These amps were rebuilt by a very knowledgeable friend and he replaced just about every original part except the transformers. The stock 12au7 tubes were changed to 6cg7's. The stock power supply caps were replaced but the old covers remain so the amps still look stock. They sound very smooth and linear with great extension. I'm using  Shuguang KT66 for the power tubes and have been rotating RCA 6C67's and Sylvania 6CG7's.

-Roy


 
Before rebuild



After:

    Roy, Your Killing Me Dude! 

    There is a magic in refurbished Vintage Amos that goes beyond specs. 

    I could just turn them on at night just to look at them. 

    Congrats, Enjoy!

[turkey]

The amp looks nice, but the way you have the speaker wires rigged is rather odd.

I've got a W3M that I should do something with one of these days. I used to have the companion preamp and matching AM tuner too, but I'm not sure if those are still around.

[Niteshade]

EYE CANDY! 

[rajacat]

Hmmm.....can I get busted for audio porn?

[JimJ]

Hmmm.....can I get busted for audio porn?

Those are over the age of consent, so you're good

[Whitese]

Those are beauties!! what is the large GE can on the bottom right of the pic replacing? its not  in the Before pic...

[rajacat]

Those are beauties!! what is the large GE can on the bottom right of the pic replacing? its not  in the Before pic...

Hi,

 Here's what the rebuilder of the W5m monoblocks says about the function of those industrial looking caps.


     "Ah, the pyranol caps.  2 reasons for their use:  1) they are rated
     at 1KV so the 450 and some odd volts will not stress them at all.
     2)  The value in microfarads was chosen to keep the B+ voltage
     right at original values.  Todays AC line voltages are higher than
     those of yesteryear so the value of the first cap in a CLC circuit
     can be adjusted down to also bring down that B+ voltage a bit.
     Also, the higher the value in microfarads in that first cap, the
     more stress it puts on the rectifier tube and the power
     transformer.  The value I picked was the best compromise to meet
     those objectives.  They do indeed replace the first section of one
     of the big can caps that we left in place for appearance."

-Roy

[7x57]

I blew a power transformer in one of my W5M amps when I left it on overnight. This is a VERY common failure of the original power transformers. I replaced them both with Hammond unpotted units and also chose a model that would drop the B+ voltage without resorting to undersized input capacitor tricks. I can use the full input capacitance of the original and keep the voltage low enough to use Tung-Sol 5881 tubes that I have a stash of.

6CG7 tubes will have a 75% failure rate in high end audio use due to high microphonics, so be careful where you buy them. Check out Andy Bowman of Vintage Tube Services. His 6CG7 tubes come with an ironclad guarantee, as he has weeded out the microphonic tubes already..

I have plenty of NOS RCA 12AU7A tubes that were matched pairs from Tektronix, so I stick with 12AU7 tubes in my W5M.

Sovtek KT-66 tubes also sound good in the W5M, but of course they are not real KT-66 tubes, just electrically similar. I also use Russian 5AR4 rectifier tubes.

[rajacat]

I haven't had any problems with the 6CG7's in my W5M's. I've used RCA's and Sylvania's. I prefer the Sylvania's. The RCAs are too tipped up in the highs and I found them mildly irritating. So far, no problem with microphonics.
   However, I did have a problem with these Russian 6L6GS equivalents (6P3S) They didn't last very long and had heavy microphonics...I think.http://www.cryoset.com/catalog/product_info.php?cPath=22_80&products_id=332&osCsid=42e74b7919bbc0ba9433f1a9405f3700
These (6P3S-E) worked much better and they're durable.
http://www.cryoset.com/catalog/product_info.php?cPath=22_80&products_id=252&osCsid=42e74b7919bbc0ba9433f1a9405f3700
I've also used several brands of KT66's.

How do the Hammonds stack up to the nickel core 16309's?
Interesting that you're using 5AR4's. I'm employing the specified 5R4 (GE). I thought about trying 5AR4's because of their greater availability and selection but I'm very timid when dealing with this amp.

[dB Cooper]

Can't see the pics 

[rajacat]

Can't see the pics 

I posted the W5m photos in 2008. Hmm...perhaps pics are somehow not available after a certain date.
I'll see if I can find them and post them again.

[rajacat]

before rebuild
after

[Wayner]

Hmmm.....can I get busted for audio porn?

Only if they are under 18.....