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SE Output xfmrs....who are the current suppliers for not many $$$

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#21
Re Shipping from Poland - I bought 2 pairs of PP output transformers, el34 and EL84 as well as 2 smaller toroids to use for bias voltage and the shipping to Canada was 117 euros. I was dealing directly with Toroidy. The electronic distributor referenced above in this thread may be able to offer lower shipping cost. Total for the 6 transformers came to somewhere around 700 Canadian with taxes. The quality is excellent. Bandwidth in the el34 Baby Huey circuit was in excess of 200khz with very little peaking in the response. On the bottom end the high inductance of the toroids allows full 20hz performance with lower distortion than typical with most small EI wound outputs.
The response to inquiries from Toroidy was fast and courteous and they gave shipping dates for any items not in stock. I believe I waited about 10 days for 1 of the items to be built. I would buy again from them with confidence.
 
#23
Tubelab_com looking forward to the bashing those Toroidy's are going to get from you.
Click to expand...

I tend to be nice to things that cost me considerable money.....cheap or free tubes are a different matter.....they get no respect.

I have built exactly one UNSET board that uses TV sweep tubes in pseudo triode mode for output, and TV IF pentodes in pseudo triode for the driver.

I tested it to 40 WPC using a pair of Hammond 1628SEA's that have been on my shelf for over 10 years. The low driving impedance of the "triode" output nearly eliminates the "Hammond notch" in the high frequency response. This made the big Hammond my favorite OPT for this amp out of 3 I tried.

The Transcendar 3K ohm OPT's that were made for 300B's were too small for 40 watts, but about the right impedance. The big Edcor 5K's that I have worked fine, and as expected had less bass and better HF than the Hammonds (size matters), but the Hammonds pulled off the best overall performance of the three, still managing to make 20 KHz at only -0.79 dB compared to the Edcor's -0.58 dB. Previous testing showed the Hammond losing 3 to 5 dB by 20 KHz.

Until now I have found no HiFi quality applications for these OPT's since the response rolls off in the HF region of the audio band when used with the typical audio output tubes.

The 1628SEA is a 5K ohm OPT which needed 650 volts of B+ to barely make 40 watts. I wanted the 3K ohm Toroidy's, but the distributor only had one in stock, so I got a pair of the 1.5K transformers. These will require two big tubes, or several smaller ones in parallel to realize their full power potential, whatever that is......I'm going to find out. Will they really make 60 watts?
 
#24
pl802 said:
After reading your #15 I feel like the master is approaching the student for assistance....I'm humbled by you.
I say Toroidy but fear post and packaging to Canada.
I have 3 sets from them.
PS Love your Altecs and envy your grandchildren who'll inherit them.
BTW what is your present amplifier or is that amplifiers?

Tubelab_com looking forward to the bashing those Toroidy's are going to get from you.
Lord have mercy!!!
Click to expand...

Thanks! Yes, the Altecs are quite wonderful, although the VOTTs need to be restored, cabinet bracing etc., they are my shop speakers now, although the shop is more like a house extension, nice wood stove, carpeted area etc. Shop amp is a Golden Tube Audio GTA-40 and/or Sophia SET-34 but have many others to choose from. 😀

I looked at the Torroidy parts, they look nice, well made and good specs, haven't inquired about shipping though.

The Hammonds are definitely cheaper from A-1, thanks for that tip, had not heard of them, but they will still be over $400 to my door for a pair of 1627SE.

Right now I think the top of my list would be Transcendar or Edcor, still waiting for a quote to make multi-tap ouput from Edcor.

So are there any good quality Chinese SE output xfmrs that you have used, are still available, and are reasonably priced?

Still -25C here and blowing snow. Back out to try to start the Bobcat and get back to plowing, I'll check back later today.

Cheers
 
#26
SE OUTPUT

Hi,

nothing but Toroidy

6V6 PSE

BLIMP%2B5.jpg


Happy new year from France

Rock
 
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#28
kilohertz said:
Thanks! Yes, the Altecs are quite wonderful, although the VOTTs need to be restored, cabinet bracing etc., they are my shop speakers now, although the shop is more like a house extension, nice wood stove, carpeted area etc. Shop amp is a Golden Tube Audio GTA-40 and/or Sophia SET-34 but have many others to choose from. 😀

I looked at the Torroidy parts, they look nice, well made and good specs, haven't inquired about shipping though.

The Hammonds are definitely cheaper from A-1, thanks for that tip, had not heard of them, but they will still be over $400 to my door for a pair of 1627SE.

Right now I think the top of my list would be Transcendar or Edcor, still waiting for a quote to make multi-tap ouput from Edcor.

So are there any good quality Chinese SE output xfmrs that you have used, are still available, and are reasonably priced?

Still -25C here and blowing snow. Back out to try to start the Bobcat and get back to plowing, I'll check back later today.

Cheers
Click to expand...

Depending on the options offered, it can be very expensive to get heavy items shipped from the US to Canada. USPS is usually way cheaper and good value if you are not in a hurry. Some companies do not offer that option and you get stuck with higher freight cost and outrageous customs brokerage fees. So make sure you know the total cost with all fees and taxes before ordering.
 
#30
Built a few amps and all were with with Hammond output transformers.


Most recent is an 845 test amp with 1638SEA's and am very happy with the sound so far.


Purchased them from digikey.ca with free shipping. Did not shop around for price.
 
#31
For best value: Edcor

I requested quotes from Toroidy (Poland), Silk Audio (Thailand), AE Europe (Netherlands) and browsed Monolith Magnetic (Belgium) prices.

Toroidy - Will give you great prices with the exchange rate. A 5k 30W SE transformer will be $50 unpotted, $100 potted with half the shipping cost of other brands to the USA. Their output transformers have high watt ratings but I do not know at what Hz. You could potentially save a lot more by ordering a custom transformer if going for something like a 2A3 SE. Also, their power transformers have very good shielding.

Silk - Very good value with lots of options, more expensive than Torroidy. They only use EI and M6 grain oriented core. While no exotic core material I believe they measure very well. And for SE the core matters less since there is no Hysteresis to worry about.

AE and Monolith. Wouldn't recommend them if you're looking for cheap. Their prices are similar with excellent quality.

Finally Plitron/Amplimo will hold it's own against the best. Many of them used to go for $800-1200 dollars. They can now be found at Menno Vanderveen's (designer) website for around 188 Euro each excluding VAT. And under a hundred euros for the lower wattage unpotted types (6-24W)
 
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#32
If you build a really nice 2A3 amplifier that you really like, you have also built a really good driver for a thoriated tungsten filament future project. Just incidentally include a coupling capacitor from the 2A3's anodes to output jacks. Safety resistor to signal ground, natch.


Have a great project, and all the best fortune,
Chris
 
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#34
Chris Hornbeck said:
.....Just incidentally include a coupling capacitor from the 2A3's anodes to output jacks. Safety resistor to signal ground, natch.
Click to expand...

Hmmm! That sounds interesting. A 2A3 amp for casual listening, and an additional 845 module to fire up for serious listening.

How would you implement such an arrangement? Would you leave the 2A3 OT connected as load (with resistor across the outputs)?
 
#39
Pegasus123 said:
Silk - Very good value with lots of options, more expensive than Torroidy. They only use EI and M6 grain oriented core. While no exotic core material I believe they measure very well. And for SE the core matters less since there is no Hysteresis to worry about.
Click to expand...

I've used silk before and have been happy with them. In my experience, quality is on par with James and better than hammond.

I've also had good luck with Kasuga out of Japan. E-kasuga.net.
 
#40
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