Mullard 3-3 voltages query - Page 3 - UK Vintage Radio Repair and Restoration Discussion Forum

Jez1234 · 17th Apr 2021, 10:51 pm

I think you mean the Quad II but yep it's very clever. I'm amazed that no one else did this... that I know of anyway!

Trevor · 18th Apr 2021, 9:32 am

Yes I did mean the Quad 2 quite correct sir
Trev

Valvepower · 18th Apr 2021, 12:05 pm

Quote:

Originally Posted by Edward Huggins

Quote:

Originally Posted by Herald1360

Quote:

Originally Posted by murphyv310

Why not try an EF37A & EL34 3-3?

Wouldn't that be a 3-6?

A variant of this was used on the (very rare) Pye Super Black Box with a SE EF86/EL34. Some cribbing of the Mullard 3-3 circuit was used by the Pye Labs.

Hello,

Ah that reminds me of the Super Black Box project of last year where I took two SBB chassis and made a stereo amplifier – as I said in the post no usable or restorable SBB’s were harmed in this exercise!

As said about the Mozart it has quite a modern sound and happily dives my KEF three way speakers.

Link to the thread.
https://www.vintage-radio.net/forum/...=175144&page=2

Ps. I actually have a SBB to restore, which I got end of last year – at present it’s in the kitchen utility area and SWMBO is getting vocal as to when it’ll find its way out the utility area and into the workshop

Terry

bikerhifinut · 18th Apr 2021, 5:12 pm

Quote:

Originally Posted by Jez1234

I think you mean the Quad II but yep it's very clever. I'm amazed that no one else did this... that I know of anyway!

McIntosh?
I think they use/used Cathode feedback in their valve amps.
Could be wrong of course.

Andy

Trevor · 18th Apr 2021, 8:15 pm

I think Mcintosh used a higher level of cathode feedback but remember this is a two edged sword if you use cathode feedback you have to increase the drive voltage
You win some you lose some
Having said that I have made some nice little amplifiers in my time
Trev

Jez1234 · 18th Apr 2021, 8:55 pm

I meant in single ended amps... but yep in push pull there's McIntosh, EAR, Papworth and some TVA (the EAR, Papworth and TVA all designed by the late great Tim de Paravicini and variations on a theme) and no doubt more...

qualityten · 19th Apr 2021, 6:14 pm

Quote:

Originally Posted by Jez1234

...the late great Tim de Paravicini ...

Oh no! I had not heard of his death. May he RIP.

17th Apr 2021, 10:51 pm	#41
Jez1234 Banned Join Date: Mar 2021 Location: Morpeth, Northumberland, UK. Posts: 936	Re: Mullard 3-3 voltages query I think you mean the Quad II but yep it's very clever. I'm amazed that no one else did this... that I know of anyway!

18th Apr 2021, 9:32 am	#42
Trevor Octode Join Date: Aug 2006 Location: Stoke-on-Trent, Staffordshire, UK. Posts: 1,082	Re: Mullard 3-3 voltages query Yes I did mean the Quad 2 quite correct sir Trev

18th Apr 2021, 8:15 pm	#45
Trevor Octode Join Date: Aug 2006 Location: Stoke-on-Trent, Staffordshire, UK. Posts: 1,082	Re: Mullard 3-3 voltages query I think Mcintosh used a higher level of cathode feedback but remember this is a two edged sword if you use cathode feedback you have to increase the drive voltage You win some you lose some Having said that I have made some nice little amplifiers in my time Trev

18th Apr 2021, 8:55 pm	#46
Jez1234 Banned Join Date: Mar 2021 Location: Morpeth, Northumberland, UK. Posts: 936	Re: Mullard 3-3 voltages query I meant in single ended amps... but yep in push pull there's McIntosh, EAR, Papworth and some TVA (the EAR, Papworth and TVA all designed by the late great Tim de Paravicini and variations on a theme) and no doubt more...