OPT for 845 tube

[45]

Ok it's clear to me that H50 is 0.5 mm lamination but don't know magnetic specs. That table is only about dimensions of laminations in any of those materials.

 

[TonyTecson]

that is why for my builds, lams 0.35 mm are used for OPT's and lams 0.5mm thick are used for power traffos,
if i wanted to do better in terms of heat, i use the rm18 and h18 for power traffos also...

 

[Celsius]

Read better popilin: I did not say "different core", but I said "different core material".
I have 4 c-cores here with exactly the same dimensions (based on SU75b geometry) but they differ in grade and/or material:
1. HiB GOSS 0.27mm;
2. HiB GOSS 0.35mm:
3. Amorphous alloy;
4. Finemet (nanocrystalline).
So I can exchange these cores using exactly the same wound coil.
This way I can do meaningfull measurements and sonic evaluation.
(My final contribution here 🙂)

news?

 

[hpeter]

New products! ⋆ Lundahl Transformers

The LL1691 and LL1691B are our most popular SE transformers for high impedance high power tubes.

However, so far these transformers have only been available with an 8 ohms secondary.
With a minor modification we have now been able to extend the above range with:
LL1691D (10k : 4, 16 ohms) and LL1691E (20k : 4, 16 ohms)

20k looks nicer

 

[alexanderfa]

Not Chris, sorry, but a 16K transformer is a real nightmare, to design and to winding, 1KV make things even more difficult but doable up to 10K. IMHO.

I have four cheap Chinese 211 (from better times) waiting for a proper 16K/8ohm transformer, so far all my attempts have failed, now I must wait to have the money for a couple of 300B (not my favourite) because of the transformer.

Hi popilin,
Can you please share your design for 16K/8ohm transformer? What you didn't like?
I have the same problem sourcing o proper output for 211

 

[pieter t]

Alexanderfa you have 2 x PM.