It's funny though in a metallurgical since thing haven't changed a whole lot from the 40 and 50's to now.
At least for most conductor they have refined the ability to keep more oxygen out of the copper but it's only been a few percent increase.
And iron well not a whole lot more to learn there then hasn't been know for almost 75 years.
The use of ferrous non ferrous mixed composition alloys were mostly created around ww2 for high frequency uses.
The big changes have been in the field of manufacturing refinements or quality control and assurance if you will. Computer process controlling has changed everything in ever type of metal industry from the massive to the obscure.
Though Mike I'm curious how advanced have they gotten in transformer winding machines or are they pretty much the same as They have been for the last 50 years?
Nick
At least for most conductor they have refined the ability to keep more oxygen out of the copper but it's only been a few percent increase.
And iron well not a whole lot more to learn there then hasn't been know for almost 75 years.
The use of ferrous non ferrous mixed composition alloys were mostly created around ww2 for high frequency uses.
The big changes have been in the field of manufacturing refinements or quality control and assurance if you will. Computer process controlling has changed everything in ever type of metal industry from the massive to the obscure.
Though Mike I'm curious how advanced have they gotten in transformer winding machines or are they pretty much the same as They have been for the last 50 years?
Nick
Re: Re: Re: Dynaco mkIII A431 op's
Hi Dan,
Well, I essentially used a ST70 circuit in one amp and a MK III circuit in the other. If you are interested you can search under my name and you will find a whole lot of details including pictures of the finished product including the transformers. I did have the original (replica) transformer covers stripped and electroplated but the the factory black finish was pretty good - it's just that I liked the electroplated look better.
As for testing, unfortunately, I only used my ears. Unfortunately, my ears are probably not that good any more after 12 years in helicopters!I do have a scope but I have not looked at the transformers - I was happy enough with the sound - this doesn't help you too much unfortunately.
It might be worth giving Matt at Triode an email. He may have some technical data and I believe him to be a really genuine honest bloke. Certainly he has always dealt very well with me and I have bought a fair bit of stuff from him.
Sorry I am not more help.
Cheers,
Rob
dan _s said:
Hi Dan,
Well, I essentially used a ST70 circuit in one amp and a MK III circuit in the other. If you are interested you can search under my name and you will find a whole lot of details including pictures of the finished product including the transformers. I did have the original (replica) transformer covers stripped and electroplated but the the factory black finish was pretty good - it's just that I liked the electroplated look better.
As for testing, unfortunately, I only used my ears. Unfortunately, my ears are probably not that good any more after 12 years in helicopters!I do have a scope but I have not looked at the transformers - I was happy enough with the sound - this doesn't help you too much unfortunately.
It might be worth giving Matt at Triode an email. He may have some technical data and I believe him to be a really genuine honest bloke. Certainly he has always dealt very well with me and I have bought a fair bit of stuff from him.
Sorry I am not more help.
Cheers,
Rob
Gammay rays
Anyone out there with imagination, a sense of humor or both might appreciate this. In the process of not buying an amplifier, spoke to someone who passed along the theory that one of the reasons the vintage transformers were so good was that now they have to dig a lot deeper for the iron ore than they did in the 50's and the stuff closer to the surface was exposed to more gamma rays.
Anyone out there with imagination, a sense of humor or both might appreciate this. In the process of not buying an amplifier, spoke to someone who passed along the theory that one of the reasons the vintage transformers were so good was that now they have to dig a lot deeper for the iron ore than they did in the 50's and the stuff closer to the surface was exposed to more gamma rays.
Hi Gregaz:
That's one I have not encountered before. Pretty good--- could lead to endless speculation of which mining sites were the best--- and--- imagine the creativity on ebay then :=)
reminds me of the age annealed copper theorem--- yet I always thought to myself that probably most copper is millions of years age annealed sitting in the earth----
probably what the proponent of age annealed copper is aiming at (I'm simply guessing) is the period of time it has for "recovery" after it has been manufactured into magnet wire. Even though this same magnet wire (as a routine process) is stress relieved via annealing to make the copper soft and non-springy as well as enhancing it's conductivity a tiny, tiny bit.
But if just pure simple "aging" works (i.e., leaving it sit somewhere) --- then man do I have some bundles of age annealed magnet wire ripening in the storehouse--- that should be worth scads of mullah--- it's the stuff that I bought way too much of ten or more years ago--- my mistakes in purchasing in other words.
And I have stumbled upon some magnet wire spools (from when Dyna's tranny maker went out of biz) that were as old as 1965. But... even this may not be old enough--- there is another school who argues that the purity of copper wire just went to the devil after say WWII.
One customer who will NOT be happy with age annealed copper is Uncle Sam. If your doing mil spec work the magnet wire cannot be more than 10 years old--- Uncle Sam apparently has a fear of insulation degradation after the wire has sat around in a warehouse for so many years.
It's a great world we live in
That's one I have not encountered before. Pretty good--- could lead to endless speculation of which mining sites were the best--- and--- imagine the creativity on ebay then :=)
reminds me of the age annealed copper theorem--- yet I always thought to myself that probably most copper is millions of years age annealed sitting in the earth----
probably what the proponent of age annealed copper is aiming at (I'm simply guessing) is the period of time it has for "recovery" after it has been manufactured into magnet wire. Even though this same magnet wire (as a routine process) is stress relieved via annealing to make the copper soft and non-springy as well as enhancing it's conductivity a tiny, tiny bit.
But if just pure simple "aging" works (i.e., leaving it sit somewhere) --- then man do I have some bundles of age annealed magnet wire ripening in the storehouse--- that should be worth scads of mullah--- it's the stuff that I bought way too much of ten or more years ago--- my mistakes in purchasing in other words.
And I have stumbled upon some magnet wire spools (from when Dyna's tranny maker went out of biz) that were as old as 1965. But... even this may not be old enough--- there is another school who argues that the purity of copper wire just went to the devil after say WWII.
One customer who will NOT be happy with age annealed copper is Uncle Sam. If your doing mil spec work the magnet wire cannot be more than 10 years old--- Uncle Sam apparently has a fear of insulation degradation after the wire has sat around in a warehouse for so many years.
It's a great world we live in
Re: Re: Re: Re: Dynaco mkIII A431 op's
thanks Rob
im also considering this Edcor Tx. it's the cheapest and oddly has the same dimensions as an A431 (dynaco mk3)
http://www.edcorusa.com/products/transformers/cxpp/cxpp100-ms-5k.html
problem is that there's too little electrical data and testimonies of people who used them
Rob11966 said:
thanks Rob
im also considering this Edcor Tx. it's the cheapest and oddly has the same dimensions as an A431 (dynaco mk3)
http://www.edcorusa.com/products/transformers/cxpp/cxpp100-ms-5k.html
problem is that there's too little electrical data and testimonies of people who used them
I don't know about vintage power output transformers (though I'm about to find out with a recently-acquired pair of HSM-189s) but I've found that old signal transformers have exemplary measured spec's. I have several military surplus Freed 11007s and Peerless 4730s (I believe - Kintel #6510039) that measure flat well beyond audibility. Mike, are you familiar with these two items?
John
John
"Age Annealing"
I can't imagine how dead soft pure copper can be annealed any further by any method. There may be specialty alloys of copper which age-anneal but more common copper alloys tend to be age-hardening. The goal of copper in electronics is to remain free of oxygen and I don't see how age can improve the situation.
John
I can't imagine how dead soft pure copper can be annealed any further by any method. There may be specialty alloys of copper which age-anneal but more common copper alloys tend to be age-hardening. The goal of copper in electronics is to remain free of oxygen and I don't see how age can improve the situation.
John
jlsem said:
Hi John:
I have prints for two of the three prints you mention above.
I have the 4730 and the HSM-189 prints.
My Freed collection consists of the majority of both their early and late audio (i.e., hi-fi) catalog offerings including the PGA and QGA series that were built in the fifties. And we have some of the really cool hi-fi OEM designs that Freed built. But--- I don't have the 11007 part number you mention which I strongly suspect is a OEM part number for Freed.
The Triad HSM-189 is a very, very nice design. I think you will like it a lot. It's a 25 watt output trans with a 10K CT primary with 50% screen taps--- so you can also parallel the two halves of the primary for 2500 ohms ct . It has secondary taps at 16, 8 and 4 ohms. It is designed with a very generous core for 25 watts--- for example it has 120% more gross core area than the 35 watt ST-70 output trans.
I could sing the praises of this Triad design for a while. Smartly interleaved. Good incremental inductance--- 160 henries at a mere 90 milliwatts of drive across the primary winding. This trans easily meets the author's specs and requirements for service in Williamson type circuits. Many of the Triad designs are IMO top shelf.
I checked and we do have the Peerless 4730 part number you mention. And it was built (as you state) for Kintel bearing their in-house part number 6510039. It's listed as an input trans with a 6.32:1 step down ratio. This design would require a lot of study time--- it is quite, quite complex. It has one of the thicker folders I recall seeing in the archives--- containing several pages of unique construction details and testing protocols. My hunch is that this may have been a mil-spec part.
MSL
jlsem said:
Yes. It's built on a EI type lamination using .006" thick 80% nickel core material. You mention that they look expensive--- I'd bet that these guys cost close to a hundred bucks each in volume over 50 years ago. It's a trick design--- it's built with twin coils. ES shields. Triple mu metal cans. It was wax impregnated. And it is wound with wire that you can barely see with the naked eye.
But I'd bee at least as excited about the HSM-189 you have. That guy looks really sharp. What are you going to build with it?
MSL
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