This TradeMe listing may interest some diy fans here

www.trademe.co.nz/electronics-photography/home-audio/amplifiers-tuners/listing-2593846885.htm?rsqid=04cdea4aa9844dd2804f02d7ee2b4568-004

Very interesting.
If some of the circuits are incomplete etc I might be able to help fill in the blanks if needed.

AMR-iFi R&D

I have some of Murray's Ecofan Bulletins & have met Pete C.

Some of Murray's designs were quite innovative I believe.
And his self-designed & self-wound OPTs, impressive performers I have been told.

DarkLantern blog - darklanternforowen.wordpress.com

Thanks for the tip-off sub 

Ecofan owner/fanboy here.



L to R:   6A3 SE stereo power amp (5w), Power Supply, for: 10 Tube Preamp. 
              (photographed together for insurance purposes only, not as used).

 
Owen: "...impressive performers I have been told."  The power amp, despite low-rated output at 5w, is indeed impressive. It's used almost daily in my second system.
I had intermittent 'static' - swapped in my Mapletree Ultra 4A SE stereo preamp and solved that. So diagnosis required within the Ecofan pre (I suspect faulty valve/s). 

"I see music as a lifetime affair." [Rory Gallagher]

Apr 18, 2020 22:51:25 GMT 12 foveaux said:

Middle shelf: Ecofan 6A3 stereo power amp, Project Maia CD and (out of sight) ELAC B5 speakers.

I've heard it said that the Ecofan 6A3 was Murray's best amp.

DarkLantern blog - darklanternforowen.wordpress.com

Apr 19, 2020 8:46:38 GMT 12 Owen Y said:

Apr 18, 2020 22:51:25 GMT 12 foveaux said:

I've heard it said that the Ecofan 6A3 was Murray's best amp.

Yep! 
I've heard loads of power amps and it'll better most on sound quality   

Here's my 6A3 in close-up:

"I see music as a lifetime affair." [Rory Gallagher]

Are those metal 6N7s?
I remember Murray ear-bashing me about the linearity of 6N7s.
Just 2 stages? Or transformer-coupled?

DarkLantern blog - darklanternforowen.wordpress.com

Apr 19, 2020 11:52:41 GMT 12 Owen Y said:

Are those metal 6N7s?
I remember Murray ear-bashing me about the linearity of 6N7s.
Just 2 stages? Or transformer-coupled?

Yes, metal 6N7's - Rogers.
From Murray's bulletin on his Single Ended Family:  "...this circuit design uses direct coupling ahead of the power valves, and a powerful 6AC7 'constant current source' for the 6N7 amplifying stage."

On your other questions, I have no idea/knowledge, Im sorry.
But again from Murray's bulletin. I hope this can be magnified and can help?:

"I see music as a lifetime affair." [Rory Gallagher]

I do remember Murray telling me (I think I have mentioned this before) that he found that a single PTX (vs 2 x mono PTXs) results in stronger bass.

I don't recall anything about the pentode CCS for the first stage though.

DarkLantern blog - darklanternforowen.wordpress.com

Apr 20, 2020 12:45:22 GMT 12 Owen Y said:

I do remember Murray telling me (I think I have mentioned this before) that he found that a single PTX (vs 2 x mono PTXs) results in stronger bass.

I used to get astonished reactions from friends when I told them my (then) Shahinian Obelisks were being driven by a 5w SE amp - all mentioned the remarkable bass performance!  

"I see music as a lifetime affair." [Rory Gallagher]

I thought I had a few Ecofan Bulletins, but I can locate only one at the moment - #11 about the incredible OTLs.

DarkLantern blog - darklanternforowen.wordpress.com

I can provide circuits of nearly all Ecofan amplifiers and copies of Murray Dick's 'Ecofan Bulletins' numbers 1 to 11. I also have circuits for amplifiers that he had working lash-ups of e.g. a SE SV811-10 (this has the same front end as his revered SE6A3), a Type 50 BSE (balanced single-ended which used conventional p-p OTs) and a 6080 SEOTL (rather like Transcendent Audio SE OTLs) having large capacitance on the 6080 dual triode output tubes. Just leave a message and your email address.

A few more thoughts on the Ecofan SE6A3. It is two stage (a bit like the direct coupled 1928 Loftin White and the much later Garber Fi2A3 from New York) and has dual mono valve rectification. As Foveaux noted the power transformer has one primary and two secondaries to fulfill the 'more iron' transformer designs that Murray Dick favoured. Although making quite a few amps with C-core output transformers he reverted to EI designs. This was because C-cores use more copper wire and therefore have greater internal resistance (the only way out of this is using thicker wire which inevitably results in a bigger transformer and a not as good hf response) and much more inter-winding capacitance (which is unavoidable and reduces hf response). (C-core power transformers also often buzz which cannot be fixed by simply strapping and earthing rolled copper around the former). It is also much more difficult to inter-weave C-core secondaries for better coupling and so EI is more efficient. Audio Note take a different view (http://www.enjoythemusic.com/magazine/manufacture/0105/index.html)and I guess that both points of view have some merit. Murray and AN agree that one problem with EI transformers at least in p-p circuits given that the 'I' is cut from the spaces in the 'E', is that the 'I' is rotated 90 degrees to form the transformer and therefore is no longer grain oriented. (As an aside after a decade of so of use it becomes grain oriented which may be why old p-p output transformers are said to sound better than new ones). But there is another problem. Whilst Radiometal is the best iron to use for p-p output transformers it saturates too readily in SE amplifiers for which non grain oriented nickel iron or preferably silicon iron is better. The other problem is SE transformers need an air gap (p-p transformers don't because they de-saturate with every negative voltage swing)to prevent saturation. A bigger air gap results in better mids but poorer lf for which the only solution is a bigger transformer which introduces further problems. Murray found that the perfect material for the air gap was a piece of the second page (i.e. the carbon copy) of an old Whitcoulls Receipt Book! No kidding. He told me once in great secrecy and I later found the reference on one of his SE schematics. So there you have an Ecofan trade secret. The proof I guess is in the listening and testing that he did. Many hours of looking at OT responses on an oscilloscope with different metals and air gaps and laborously plotting the results on pieces of paper. The other proof is within his amps. The SE6A3 for example has a flat frequency response from well below 20hz to over well over 65kz. Beat that Audionote! The more expensive AN amplifiers use triple C-cores - two for the primary and one for the secondary - which might get over some of the problems that Murray identified but at a price.

A warm welcome to the forum Peter.
Looking forward to your contributions. And have valued your kind offer and your first info. on Ecofan.
Enjoyed this gem:
"Murray found that the perfect material for the air gap was a piece of the second page (i.e. the carbon copy) of an old Whitcoulls Receipt Book! No kidding. He told me once in great secrecy and I later found the reference on one of his SE schematics. So there you have an Ecofan trade secret."

I endorse your comment "The proof I guess is in the listening."
As noted earlier about my 6A3: 'I've heard loads of power amps and it'll better most on sound quality.'  It sounds superb. (thanks Whitcoulls ).

"I see music as a lifetime affair." [Rory Gallagher]

I am very interested in the pre amplifier with 4 ecc88 and 2 12bh7A tubes. I presume the pre amplifier line stage uses the 12bh7A, since replacing these has increased the performance on non-phono. It sounds considerably louder, more attack and better clarity. Also the audion 6l6 converted to kt66. My email address is [e-mail]

I would be very happy to get the circuits for audion 6l6 (converted to kt66) and the accompanying pre amplifier using 4 ecc88 and 2 12bh7A tubes. I recently bought these and love their sound.

Hi Gazarado
Sorry for the slow reply. I logged in tonight for the first time for some weeks. I'll have a look at the Ecofan circuits tomorrow to see whether I have a match. Although the decal on your father in law's amp reads 6L6, the amp itself was more usually a EL34. Murray simply used 6L6 decals that he had printed for the first batch (probably 8) of the EL34 amps which were designated as "Mark 111". The second batch were correctly marked EL34 and he did make at least one amp using KT66s. The KT66 amp was distinguished by having C-Core output transformers which were set in a can. The other 6L6/EL34 amps had EI output transformers on which you can see the iron stack. I can certainly provide the circuit for the Mark 111 but probably only the EL34 version. I don't know of an Ecofan preamp using four ECC88's and two 12BH7 valves but I'll have a look. Perhaps it has been modified as the 12BH7 is very close to ECC82's. Maybe send me a photo to [e-mail]. Incidentally I was probably the person who returned the Ecofan to your father in law as well as about 20 other incomplete repairs!

I don't have a father in law fitting your description. I have sent an email re amplifier and pre. I assume the 12bh7A is the general pre amp side, and the ecc88 for phono stage (4 for MC). Wasn't aware of Murray's building of these Audions particulars with 6l6 and EL34. The KT66 and pre sounds very nice. Was the pre using ecc82 originally? I read the 12bh7A is a better tube overall. I originally thought the 12bh7a was phono related. I am new to valves, and am learning as much as possible to get the amp working optimally.