DIY PPP 6V6 Amp

RE: DIY PPP 6V6 Amp, posted on January 6, 2017 at 12:25:42
gusser Audiophile Posts: 3649 Location: So. California Joined: September 6, 2006	Looks good but I would finish it off by throwing three junk tubes in those empty holes - even light them up if you have the reserve filament capacity.

RE: DIY PPP 6V6 Amp, posted on January 6, 2017 at 12:32:19
sony6060 Audiophile Posts: 1465 Location: USA Joined: August 8, 2014	9 pin sockets should be here today. It uses three Raytheon 6CG7. Two phase splitters and one preamp.

RE: DIY PPP 6V6 Amp, posted on January 6, 2017 at 13:46:13
gusser Audiophile Posts: 3649 Location: So. California Joined: September 6, 2006	Oh, OK. Looking a little closer those big tubes must then be 5U4'S? I initially though they may have been some big triode for input and phase split.

RE: DIY PPP 6V6 Amp, posted on January 6, 2017 at 13:54:34
sony6060 Audiophile Posts: 1465 Location: USA Joined: August 8, 2014	Actually RCA 5V4G. I run in parallel due to high current draw of amp. I use a choke input PS with 5Hy @ 500ma choke & a true paper/oil cap. RCA 5V4G sounds better than a Mullard GZ34 per a few audiophiles.

RE: DIY PPP 6V6 Amp, posted on January 7, 2017 at 09:23:26
Palustris Audiophile Posts: 2408 Location: Cape Cod Joined: September 12, 2008	"RCA 5V4G sounds better than a Mullard GZ34 per a few audiophiles." I would encourage you to test for yourself. In my tests the 5V4G was my least favorite rectifier with the most compressed dynamics. The Mullard GZ34 and a generic 5V3A were the best sounding rectifiers and there was very little difference between the two.

RE: DIY PPP 6V6 Amp, posted on January 7, 2017 at 11:38:34
sony6060 Audiophile Posts: 1465 Location: USA Joined: August 8, 2014	I have enough filament power. I will try 2x RCA 5V3A.

RE: DIY PPP 6V6 Amp, posted on January 11, 2017 at 20:19:31

drlowmu
Manufacturer

Posts: 9730
Location: East of Kansas City
Joined: January 10, 2005

Cease and desist. I think your lay-out is in need of great improvement.

That needs to be a dual mono amp. Existing chassis is really too small. All the fields from the iron will be interfering and interacting between themselves, and with everything else in the amp.

Are those ST-shaped tubes your rectifiers?? If so, WHY are they on either side of the amp ???? Form follows function. Fix that.

A 5V3A is a nice sounding DIRECTLY heated rectifier, but it will raise the B+ VDC versus other rectifiers, so PSUD that out. If it does raise it above what you prefer, look into using a new Electro Harmonics 5U4GB, another directly heated rectifier tube, available for $13.50 from Antique Electronic Supple in AZ. I plan to order some soon from them.

Once you build dual mono, or better yet, true monoblocks, you will NEVER build a shared supply amp again ! Why ?? There is a clarity obtainable with a non-shared supply, that you will NOT hear / obtain, through any other lesser means. Do not waste your time and waste your life using shared supply power amps!! Do it RIGHT !!

The RCA input jack needs to be located within 2 inches of the grid of the input tube.

Re-do the chassis, re-do the lay out, keep the same tube complement.

From my early stock market, / stock-broker days, I learned this - sometimes your first loss is your best loss !!

Have fun, I certainly sure am. Best wishes.

Jeff Medwin

6V6 Amp- my design vs drlowmu design, posted on January 11, 2017 at 21:05:18

sony6060
Audiophile

Posts: 1465
Location: USA
Joined: August 8, 2014

I built this amp as monoblocks before. Sounded good.

A lot more thought went into this amp that is not apparent in the picture. Being PP type, symmetrical is very important and more so than your SE amps. The power supply is not as critical as SE amps, but is of good design.

On a stereo chassis I tried separate power supplies for each channel and did not like the sound. Some others also like a single power supply vs two on same chassis. Unless monoblocks, two separate power supplies is a mistake on one chassis IMO.

Transformer and choke will have a ferrite lined steel cage. Under chassis top will also have a ferrite shield. Fields will not interfere with each other. Audio transformers will be outside the ferrite shield. This is a choke input power supply. Choke is rated 1.5 x the current being used. A second choke & oil capacitor separates the next stage from power tube stage. Paper/oil caps are used through out.

All leads will be same length. That is why the symmetrical layout. Lead length is important as you know.

Power supply and Heyboer M6 lamination custom transformer has been calculated in PSU2. B+ current capacity is more than double the demand. Choke is 27 ohms or close to your 20 ohm limit.

Input jack that will be in the front center is about two inches from input tube.

All wiring is silver including the ground wire. The ground is placed above the 6CG7s on ceramic standoffs for equal length to all amp grounds. The power supply ground connects at the far end and the ground terminates to chassis only at the input jacks.

The amp will perform fine and layout is not only symmetrical, it is shielded to the point it acts like it is 3 feet square, but without bad news long lead lengths. The ferrite shields allow this short lead length. Which is more evil, long leads or ferrite sheet shielding.

Rectifiers are 5V4G. The rectifiers can be placed anywhere. It has no effect as to the location IMO.

RE: 6V6 Amp- my design vs drlowmu design, posted on January 11, 2017 at 22:09:26

sony6060
Audiophile

Posts: 1465
Location: USA
Joined: August 8, 2014

BTW- The shielding is called Giron. It will take the transformer and choke down to about zero AC field with two layers. I might as well have the power transformer & choke a 100 feet from the chassis.

I also use a Corcom AC line filter.

RE: 6V6 Amp- my design vs drlowmu design, posted on January 12, 2017 at 06:33:19

drlowmu
Manufacturer

Posts: 9730
Location: East of Kansas City
Joined: January 10, 2005

Thanks for the explanation, and I totally appreciate all the thought and care you put into this build.

A+++.

ALL silver wire is not needed, but silver is NICE in critical spots, I use a lot of m22759/11 these days, but I DO use silver in three spots (1) RCA jack to grid of input tube, doubled-up (2) My direct couple, about 19 AWG, tripled-up and (3) off the center tap of my DHT Ef XFR, tripled-up, under 2.5 inches, to the top of the 2A3's Rk resistor.

I hope you get great performance.

In my early DIY years, Bob Fulton mentored me on a P-P-P 6B4G amp, six outputs per channel and it was on eight chassis, weighed about 700 hundred pounds. Wouldn't play the big Fulton speakers at high levels. Now a days, ALTEC VOTT A7-800s and a single JJ 2A3-40 for Finals. Coming up soon, Q1 or Q2 - 2017, monoblock JJ 2A3-40 amps.

Have fun, I am !!

Jeff

RE: 6V6 Amp- my design vs drlowmu design, posted on January 12, 2017 at 13:06:39
rage Audiophile Posts: 793 Joined: December 17, 2010	Is the M6 transformer your PT or outputs? Count me a fan of Heyboer!

RE: 6V6 Amp- my design vs drlowmu design, posted on January 12, 2017 at 13:28:22

sony6060
Audiophile

Posts: 1465
Location: USA
Joined: August 8, 2014

M6 lamination power transformer was custom built by Heyboer Transformer. M6 provides more power output in smaller package vs standard power transformer M19 laminations.

The output transformers are Dynaco ST-70 (A-470) new manufacture exactly to old specs including winding turns, gage of wire, interleaves, etc from Triode Electronics. It is a great sounding transformer and accurate. Many audiophiles do not know this. Most audio transformers use M6 laminations.

RE: 6V6 Amp- my design vs drlowmu design, posted on January 12, 2017 at 13:30:46
rage Audiophile Posts: 793 Joined: December 17, 2010	I'm toying with remade Z565....haven't played with A470. The original Dynaco 70 circuit sure did measure well...damn popular amp as well...probably for a reason! I like your build!!!

RE: 6V6 Amp- my design vs drlowmu design, posted on January 12, 2017 at 13:41:29
sony6060 Audiophile Posts: 1465 Location: USA Joined: August 8, 2014	Z565 are one of the best audio transformers ever built.

RE: 6V6 Amp- my design vs drlowmu design, posted on January 16, 2017 at 04:03:09

PakProtector
Audiophile

Posts: 12365
Joined: May 14, 2002

I found the Z565 to have a very characteristic sonic fingerprint. Even with radically different topologies. I built an amp with a pair, and then upgraded to an output wound exactly like a Peerless S-265-Q, but with taps 20, 30% instead of the OE 50%. They cleaned the Z565's clock, and I got another pair made for the 4E27 amps, and got those with 20, 30 and 40% taps.
cheers,
Douglas

Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.

RE: 6V6 Amp- my design vs drlowmu design, posted on January 16, 2017 at 06:58:44

sony6060
Audiophile

Posts: 1465
Location: USA
Joined: August 8, 2014

Interesting. At Electron One transformer tests the Z-565 had about a perfect square wave output and the Peerless had overshoot on the square wave test.

The Z565 are $190 a pair and the Peerless is about $1200 a pair if MagnaQuest still builds them.

Personally, I think the Dynaco A-431 sounds better than the Z565, but the A-431 are lower P to P impedance.

If the Peerless sound as good as you state, they are worth the money.

RE: 6V6 Amp- my design vs drlowmu design, posted on January 18, 2017 at 03:51:08
PakProtector Audiophile Posts: 12365 Joined: May 14, 2002	What you may discover at some point is that a winding house with an NC winder, and the winding details gotten from taking apart a transformer can make copies of anything that is put in their hands. I supplied an S265Q, and had them made in pairs a few times...:) cheers, Douglas Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.

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DIY PPP 6V6 Amp

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