ampage
Tube Amps / Music Electronics
For current discussions, please visit Music Electronics Forum.

ampage archive

Vintage threads from the first ten years

Search for:  Mode:  

Re: OT design


 :
4/22/1999 8:37 AM
Bob S
Re: OT design
I don't know very much about this, but I've been told there's a rating for lamenations on transfomers. My understanding it may have to do with dampning values. I spoke with Ken Fisher a couple of years ago and he said he used the #6 lamanent as opposed to #22 as used by Fender. I've had it confirmed by a guy I know who is a transfomer builder, who told me most all of the english amps used the #6 for their transformers. Maybe that's part of the reason english amps typically have a tighter sound.(More dampning from the transfomer. Not enough dampning provided by feed backloop.  
 
Bob S.
 
Today
ampage
archive
And now, a word from our sponsors:


 
4/22/1999 11:30 AM
SpeedRacer

Do you know which scale he's referring to?  
The US seems to use an 'M#" system, where I've heard of "H#"'s being used for european lams. In the US system, higher #'s are generally "cheaper" material. M6 from what I understand is used in hifi stuff and all else equal will give a higher primary inductance than say an M15. I don't know about any effects on dampening, but your LF rolloff will get lower and lower as your lams get better (for the same coil assembly)
 
4/22/1999 12:21 PM
R.G.


I'd have to know more about what the "#6" and "#22" you're talking about mean. That doesn't correspond to anything I remember about laminations, and I did work with them for a number of years. Maybe M6 or M22? I believe these refer to either the metallic alloy of iron or the lamination thickness, I'll have to go look it up. It's entirely likely that the Brits have a different nomenclature system for both alloy and thickness.  
 
In any case, the lamination can affect low frequency response, but the effects of core material are confined to the amount and linearity of the primary inductance and the core losses. They really can't affect the amplifier damping factor in the way you mention.
 
4/23/1999 10:10 AM
Bob S

I believe it has to do with the alloys but not exactly sure. Ken Fisher acted like it was a very special thing but when I spoke with my contact in Texas about winding some trans. for me he calmly said "Oh that's what Marshall uses on all their transfomers" so I thought it was common knowledge. Oh by the way,my contact in Texas is a guy named John Surniak and is pretty well known in the Dallas area. His company is called Electro Magnetics.  
 
Bob S.
 
4/24/1999 9:25 PM
SpeedRacer

The "M" scale is an ASTM scale that groups the iron alloys by core loss and permeability. M6 is an approx 3% Si steel, while the others are non-silicon. (softer, and more popular with the stamping shop!) What I found in my digging was that even when you (the xfmr mfr) order #22, you can be sent anything equal or better by the steel mill. I'm told this is the "industry standard". Just one more bit of "slop" in the "perfect amp formula". Musical laminations. :-)  
Lams come in two thicknesses currently, 24 & 26ga. M6 only comes in one (I forget which one..)
 
4/26/1999 11:09 AM
SpeedRacer

..getting some dissention in the transformer world on these "facts". The jury is still out.  
More later as we get our facts straight.
 
4/26/1999 2:16 PM
R.G.

Lamination availablity
Thanks for the current view. My experience with buying lams is quite a few years old, and the MBA's have had that much time to channel products into only high-volume, high-profit items and discontinue anything that is "marginal" - that is, not a higher rate of return than the stock market.  
 
The MBA's keep trying to run the market like Lake Woebegon - where all the children are above average.
 

<<First Page<PrevPage 2 of 4 Next> Last Page>>