audio-talk

andrew Ivimey wrote: Tue Dec 10, 2024 8:07 pm I went back to 45s. And this is where lundhal 1660 ( offered the Amity/Karna) came in; simple single triode input through 1660 to 45push pull output- it was more than enough - glorious ( but I doubt its remembered at Owston )

I remember it well….very shoddy!

What does the phase look like?

One possibility would be monolith magnetics, either IT-02, ITA-02 or ITX-02
Tell them you are going parafeed so you will need access to four terminals on the primary. Also four terminals on the secondary if you want to bias the output tubes separately?
Also discuss if you want a gap - probably gap ...

Paul Barker wrote: Sat Dec 07, 2024 9:09 am Stephie started balanced and output tube was single ended. 845. What am I saying? The blend can go either way.

Good point. Avoids the phase splitter. Do you have a link to that Stephie amp?

A third option is to parafeed the Llundall’s I bought before Mark warned me against them. But maybe parafeed worth experimenting.


I may have made this up in my head, but I seem to remember Lundahls being a bit of a mixed bag (and I think this was interstage as well as output). But they released ...

I realized the solution was to have a power amp that just added power to the signal with as little as possible error, and then add that magic with a DAC and phono stage with a valve output that added a little of that magic with far less added problems.


Another option could be push-pull amps ...

Good news that it’s treatable Ray, and I’m full of admiration for your PMA. We’re thinking of you.

I'll wade in. Possibly a foolish idea.

Caps are odd things. I dislike them as coupling devices. If I have to have them, personal choice would be film and foil, not metalised. I have one amplification coupling cap.

However I'm not averse to electrolytics in power supplies for differential ...

That really does finish it off nicely!

Cressy Snr wrote: Thu Dec 05, 2024 3:28 pm Just put a Fender jewel light on the front of the HPA. That's better
I can't have a valve amp without a Fender jewel glowing away on the front panel; it's just not cricket!

We need a picture!

Nick wrote: Thu Dec 05, 2024 10:09 am

There is then the question - 'do we think that a capacitor made of copper (or silver) wires plus enamel is a 'good' (objectively and subjectively) capacitor?'

Not touching that one

Fair enough

Morgan was saying about bridging transformers with a small cap. The Hammond is bifilar so both windings side by side, surely is equivalent of bridging with a capacitor? But I am prepared to try small caps.


Yep, I have always believed that bifilar is just a way of smuggling a distributed cap ...

5/ grid resistance, WE for fixed bias limit is 50kohm. I see diode bias as fixed bias erring on the side of safety. I bet many of you never seen that limitation? Now I see where the figure suggested on a forum for fixed bias GM70 is 50kohm . I would suggest that may be too high.


Hi Paul. I'm ...

Does this help?
https://www.sowter.co.uk/rectifier-tran ... lation.php

Blore Edwards currently offering 10% off for Black Friday
promo code 'Black10' - I think its only today and tomorrow
I did a quick test and it did knock 10% off at checkout on a LL1627AM