[Hogg]

I apologize, if this topic has been discussed.  I'm interested in tube amplifier transformers.  My question is why antique "iron" is so dear to many audiophiles.  One would think modern manufacturing techniques, metallurgy and the on-going march of technology would render the old "iron" useless.  I see many Dynaco amps for sale with old "iron" instead of new transformers.   Will someone please enlighten me?  Thank you.

                               Jim

[Niteshade]

There is only one reason and that's to do with construction quality. I have ran across vintage iron both heavy and not so heavy that has incredible sonic properties. Back when tubes were the primary amplification source, there were magnitudes more components to choose from AND it was much less expensive to make high quality parts. The net result typically was superior quality transformers. Poor transformers were indeed made back in the tube amp days, so this trend isn't for all vintage transformers.

Modern decently priced transformers are good! However, if you were to compare a 60's high end transformer to a 00's high end transformer, you'd find the newer one lighter in many cases. I've found a mass reduction of around 25% in some cases OR a reduction in frequency response (AKA: Hammond's modern line).  This is NOT the general rule, but it sticks with reasonably priced high performance transformers most of the time. I have seen modern transformers just as good as vintage ones and maybe better. 

Here's something to think about:  I have seen vintage Rowland commercial 100 watt tube amplifiers. They weigh 80lbs each. Both the output and power transformers are ENORMOUS- around 3x's the size of any 100 watt iron I have seen today. These are 60's amps. The output iron weighs around 40lbs alone. Fisher and Scott used to use enormous output transformers in their 35 watt/channel receivers. (Fisher 500C & Scott 340B) It was nearly the same size as modern 50 watt iron.

On the opposite side of the spectrum comes in Hammond's vintage small industrial transformers for EL84's. They're not much bigger than a golf ball. They appear cheap and dinky. That's a modern stereotype and 100% wrong in regards to these gems. It's soooooo wrong! They have a wide, linear response that takes a modern 10 pounder to compare with. They are very efficient as well as linear.

So- some of what you hear is wives tales, some of what you hear is blanket statements that shouldn't cover ALL vintage transformers. A statements such as, "All vintage iron is better than modern iron" is not true. You have to know what to look for.

[richidoo]

Who makes great new transformers for DIY nowadays?  I see many ads in AudioXpress.
Thanks

[jtwrace]

Who makes great new transformers for DIY nowadays?  I see many ads in AudioXpress.
Thanks

I know that Kevin at K&K s the Lundahl importer.  http://kandkaudio.com/transformers.html

[Niteshade]

Edcor is my favorite for good transformers. Their quality is consistent and they have several models to choose from. I like One Electron for low power single ended apps. These closely resemble vintage high quality single ended outputs. They're massive for their wattage rating.

[JoshK]

I apologize, if this topic has been discussed.  I'm interested in tube amplifier transformers.  My question is why antique "iron" is so dear to many audiophiles.  One would think modern manufacturing techniques, metallurgy and the on-going march of technology would render the old "iron" useless.  I see many Dynaco amps for sale with old "iron" instead of new transformers.   Will someone please enlighten me?  Thank you.

                               Jim

I think there is some truth in this and some fiction/dogma/whatever you want to call it.  I believe  that manufacturing of iron was less capital intensive back in the days when it was manufactured in economies of scale.  Therefore it was possible to make higher quality transformers that incurred higher manufacturing costs when those costs could be spread out over many more sales.

Lots of big business nowadays looks at optimizing on cheapest to manufacture and cut costs, cut costs, cut costs.  Sure, technological advancement means that a lot of that cost cutting doesn't have to eat away at performance of the end product to the same extent, but I think it is a balancing act.

I think the crowd that chases vintage iron believes that vintage iron is superior for the following reasons:
1) that the iron itself was a higher quality iron.  This affect permeability.  Material costs have gone up generally more than inflation it seems, so higher quality iron was cheaper to acquire back then.  Ever seen the price of transformers that boast of use of superior Japanese iron? 
2) some believe that more care was spent on windings to optimize bandwidth.  The Citation II is a clear example of where the engineer went to great lengths to optimize the bandwidth of the output iron.  No off the shelf Hammond OPT has even remotely the same bandwidth, although plitron toriodal OPTs would probably wipe the table with the Cit II iron (in terms of bandwidth) if the design was careful in DC balancing.

I think the first is probably the most noted reason, although I've seen some tube mailing groups that tout the 2nd. 

Modern manufacturing can get very tight tolerances on whatever, but it may not be cost effective in small quantities to do so. 

In the end, I've never measured the performance of the modern versus the vintage to know which is better.  I think there is definitely some truth that some of the vintage iron is better than the cheaper modern stuff, but it isn't across the board and some of the vintage iron prices have mitigated the price advantage over ordering the top shelf modern iron.

[JoshK]

Lots of modern iron choices

1) Hashimoto
2) Edcor
3) Lundahl
4) One Electron
5) Onetics
6) Tamura
7) James
Hammond
9) Plitron
10) Antek
11) Electraprint
12) Magnequest
13) Silk
14) Heyboer
15) Tribute
16) Transcendent

Then there are a lot of chinese iron jobbies on ebay and there are some quality Italian makers that I can't remember the names of, one that starts with a B.  Those are just the ones off the top of my head.  I am sure I forgot some.

[poseidonsvoice]

Who makes great new transformers for DIY nowadays?  I see many ads in AudioXpress.
Thanks

I know that Kevin at K&K s the Lundahl importer.  http://kandkaudio.com/transformers.html

I'm currently building a differential push pull Class A1 EL34 designed by Kevin Carter using Lundahl cobalt amorphous core input transformers and Bud Purvine's O-Netics Level 2 output transformers. Input/driver stage is capacitor coupled to the output stage.

Lundahl, O-Netics, Magnequest, and Electraprint have always been on my short list. You can't go wrong with either of them, but you'll pay,pay,pay. There are a ton others available, pm me if you really want to know. See Josh K's list!

Anand.

[richidoo]

I found this simple explanation of OPTs while wandering around at Plitron:
http://www.plitron.com/PDF/Atcl_1.pdf
Thanks

[nullspace]

Magnequest has been mentioned a couple of times, but I'll bring up Mike's name again. He makes some really nice stuff, and he's local to me (Phila., PA).

A mfg not named is Heyboer; I get all my DC supply iron from them. Prices are competitive with Hammond, and everything is custom. Need 750Vct @250mA, 6.3Vct @ 3.6A, 6.3Vct @ 925mA, 2.5Vct @ 5A? You got it, for $110 a piece. 12H @ 250mA,  ~120ohms DCR and suitable for choke-input? $70 each. Here's the process; I send them an email with my requirements, Alden sends me an email with a price quote, and then I agree to said price. Two weeks later or so, the iron shows up on my doorstep. A couple days after that, the bill arrives. Honestly, they're really great to deal with.

Regards,
John

[JoshK]

hey, I said Heyboer. 

[JimJ]

Magnequest has been mentioned a couple of times, but I'll bring up Mike's name again. He makes some really nice stuff, and he's local to me (Phila., PA).

A mfg not named is Heyboer; I get all my DC supply iron from them. Prices are competitive with Hammond, and everything is custom. Need 750Vct @120mA, 6.3Vct @ 3.6A, 6.3Vct @ 925mA, 2.5Vct @ 5A? You got it, for $110 a piece. 12H @ 250mA,  ~120ohms DCR and suitable for choke-input? $70 each. Here's the process; I send them an email with my requirements, Alden sends me an email with a price quote, and then I agree to said price. Two weeks later or so, the iron shows up on my doorstep. A couple days after that, the bill arrives. Honestly, they're really great to deal with.

Regards,
John

How's the quality? No problems with lams humming or anything like that?

Trying to decide between Edcor or maybe something else for the PT for my next project...

[nullspace]

hey, I said Heyboer. 

Ah, I missed that. You're the man, Josh...

How's the quality? No problems with lams humming or anything like that?

Trying to decide between Edcor or maybe something else for the PT for my next project...

To date, quality has been very good. Specs have been met in every instance -- I've gotten stuff from them on 5 or 6 occasions now. No problems with hum or buzz; I will say that I typically pad the DC current ratings for the PTs by 10-15% and since I generally use choke-input power supplies make a point of ordering chokes rated to handle unbalanced DC + peak AC ripple current. Regulation tends to be very good; around 5%.

I just got a pair of power transformers to rebuild a 45 amp of mine, and I had Heyboer do them in M6 in a drop-through chasis w/ solder terminals, and they came out really nice. Cosmetics aren't as nice as the MQ stuff, but for the price I wouldn't expect it to be.

I have never used Edcor, so I can't compare one against the other.

Regards,
John

[JoshK]

I forgot the Dyna clones that you get from Triode Electric.  Said to be pretty good.

Also Intact Audio by Dave Slagle.

[Curly Woods]

Deleted by author

[rlee8394]

Toroid Corporation of Maryland. Check out their two standard tube trannies here:

http://www.toroid.com/standard_transformers/rectifier_transformers/rectifier_transformers_tube.htm

Ron