Yeah, I thought of that as soon as I got the invoice with $32 shipping. They are now in the hands of UPS, but still in Poland. Still, a pair of SE OPT's that do 30 to 50 watts each for $208 shipped is a deal...if they work out.
I'm not in a big hurry anyway since I seem to be the IT guy for the extended family...everyone wants their free Windows 10 upgrade before it goes away.
Depending on how the transformers work out, I'll remember the "order one at a time" trick next time.
I am looking forward to your findings after you put the Toroidy SE OTs through you tests. I’m hoping there is a TSEII in my future.
Edcor has been very useful to me. I needed to find a way to drive a variable impedance load without having the transformer cause issues. It was not an issue.. but I needed calling their tech support, and talked to Brian there. Here are some facts on the Edcor audio transformers, and it applies also to the speaker-to-line matching ones which go up to 600W.
Their stated frequency response is the +/-1dB power bandwidth, not some lowest-power marketing rating.
40-20,000Hz +/-1dB for the 100, 200, and 400W, 140V-line-to-speaker units I bought.
M6 steel used, 29 gauge laminations (0.0135 inch, 0.34 mm), (Grain) line oriented
Virgin copper wire (no recycled copper). Essex is the main source manufacturer of wire. Chinese wire is very often recycled and impure -so not used.
glass filled nylon bobbins
interleaved windings on all audio products.
Edcor used to make amplifiers, and at first was buying the OPTs from another company, but then they started making them in-house with quite higher quality than the usual "PA" amp transformer and people were buying the amps more frequently because of the sound quality. OK well solid state public address and hi-fi amps became dime a dozen from China, so Edcor focuses only on making high quality transformers. I think it's the best for the $.
Their stated frequency response is the +/-1dB power bandwidth, not some lowest-power marketing rating.
40-20,000Hz +/-1dB for the 100, 200, and 400W, 140V-line-to-speaker units I bought.
M6 steel used, 29 gauge laminations (0.0135 inch, 0.34 mm), (Grain) line oriented
Virgin copper wire (no recycled copper). Essex is the main source manufacturer of wire. Chinese wire is very often recycled and impure -so not used.
glass filled nylon bobbins
interleaved windings on all audio products.
Edcor used to make amplifiers, and at first was buying the OPTs from another company, but then they started making them in-house with quite higher quality than the usual "PA" amp transformer and people were buying the amps more frequently because of the sound quality. OK well solid state public address and hi-fi amps became dime a dozen from China, so Edcor focuses only on making high quality transformers. I think it's the best for the $.
Many transformer manufacturers rate the high and low frequencies at -3 dB.
Many amplifier manufacturers do the same.
Some rate +/- 1 dB. That is better than - 3 dB.
Since most good transformers, and most good amplifiers, have smooth frequency response curves, that means that +/- 1 dB is the same as +0 dB / -2 dB.
(0 dB at midband)
That is because if you have any ripple in the frequency response curve at or near midband, then that product is not good.
It is a marketing thing:
+/- 1 dB sounds better than +0 dB / - 2 dB, but most of the time they are equal and the same thing.
Many amplifier manufacturers do the same.
Some rate +/- 1 dB. That is better than - 3 dB.
Since most good transformers, and most good amplifiers, have smooth frequency response curves, that means that +/- 1 dB is the same as +0 dB / -2 dB.
(0 dB at midband)
That is because if you have any ripple in the frequency response curve at or near midband, then that product is not good.
It is a marketing thing:
+/- 1 dB sounds better than +0 dB / - 2 dB, but most of the time they are equal and the same thing.
Oh, SE stuff, oh well sorry about that. I only do PP here. duh.
but the same specs, pretty good. The OPTs do 20Hz..
Wattage 25W
Max. Current 200mA
Primary (input) Impedance 3K Ohms
Primary (input) DCR 70 Ohms
Primary (input) Inductance 41H
Screen/Grid Tap 40%
Secondary (output) Impedance Depends on model.
Secondary (output) DCR <1 Ohm
Frequency Response 20~20K Hz., <1dBu
$<100
just the line units I bought do 40.
but the same specs, pretty good. The OPTs do 20Hz..
Wattage 25W
Max. Current 200mA
Primary (input) Impedance 3K Ohms
Primary (input) DCR 70 Ohms
Primary (input) Inductance 41H
Screen/Grid Tap 40%
Secondary (output) Impedance Depends on model.
Secondary (output) DCR <1 Ohm
Frequency Response 20~20K Hz., <1dBu
$<100
just the line units I bought do 40.
Nomenclature:
0 dBu was commonly used in the 600 Ohm Audio industry.
It meant 1 milliwatt into 600 Ohms.
That is something like 0.775Vrms.
It turns out that many "600 Ohm" audio board inputs, etc. no longer terminate in 600 Ohms. They are high impedance inputs.
0 dBu is 0.775 Volts rms, so 1 dBu is 0.869V rms.
dBu and dBV are not the same term.
1dBu may not be a good term for audio power amplifiers, nor for powerful output transformers. That is a mis-nomer.
Yes, it is mis-used by some manufacturers that do not seem to have a clue.
Try not to repeat mis-nomers, they confuse the less knowledgeable.
If a frequency rating is <1dBu, what does that mean?
< +0/-1 dB?
I am just wondering.
0 dBu was commonly used in the 600 Ohm Audio industry.
It meant 1 milliwatt into 600 Ohms.
That is something like 0.775Vrms.
It turns out that many "600 Ohm" audio board inputs, etc. no longer terminate in 600 Ohms. They are high impedance inputs.
0 dBu is 0.775 Volts rms, so 1 dBu is 0.869V rms.
dBu and dBV are not the same term.
1dBu may not be a good term for audio power amplifiers, nor for powerful output transformers. That is a mis-nomer.
Yes, it is mis-used by some manufacturers that do not seem to have a clue.
Try not to repeat mis-nomers, they confuse the less knowledgeable.
If a frequency rating is <1dBu, what does that mean?
< +0/-1 dB?
I am just wondering.
It is an entirely DIY thing that isn't documented and just started working sometime in October of last year. Who knows how long it will last, but it worked yesterday.
You need a working computer that meets the W10 requirements. I have done Pentium's and Core i3's that don't meet the requirements and they work fine.
It's best that the computer has W7 on it, but it can be done on a freshly built machine if you have a set of working W7 product keys.....that string of 5 five digit characters on the Windows sticker....or from old W7 install disk that you aren't using any more. If your W7 PC does not have the Windows sticker on it, it's possible to extract the keys from the Windows registry with a free program. I used one called magical jelly bean keyfinder.
Magical Jelly Bean Keyfinder 2.0.10.13 Download - TechSpot
Once you have a PC and a set of W7 keys (Vista and XP keys do NOT work, I tried), you need a W10 install disk or flash drive. You can buy one from MS for $$$, or you can download it for FREE directly from Microsoft!
Download Windows 10
Use the method explained about halfway down the page to create a DVD or flash drive W10 installer. I tried both and they both work. Once you make them you can use them for several machines.
Boot the target machine from the flash disk or DVD, follow the clean install or upgrade instructions, and type in your W7 key when it asks you for a key.
Note, I found two sets of keys that did not work. Both were "Invalid keys." Both were in used but "refurbished" W7 laptops purchased from Newegg. My guess is that these were never actually refurbished, just "restored" to the state they were in when new, and they were likely originally purchased under a blanket corporate license, and not eligible for an upgrade.
I even used the W7 keys from the sticker on a dead Toshiba laptop to do a clean install on a new machine.
They sell Win 10 keys on ebay for just a few pounds.
I didn't have any trouble with the last one I bought.
Very cool to see prototypes of the TSE amps!! Fine, attractive vintage components mixed with contemporary parts, seamlessly! Just a side story here but I saw a pair of mono deHaviland prototypes years ago at a club meeting is San Francisco. They were Altec 1570 amps, with same power transformer, 4 rectifier tubes, plus single huge PIO caps, big single ended transformers, and 1 each GM70 tube. A man was showing and playing them, not the lady CEO. Doc Edgar was there, along with a sub-horn the size of a refrigerator, L + R speakers, and small attractive amps. Well, these GM70 amps were hooked up instead, despite his mild protests. WOW! It was a knockout. (first GM70s I'd heard). This was the same club that One Electron DIY classes were held a few years before. Back to salvage, I came across many types of chokes and PIO caps. Many 4 and 6 uFs, but 'GE Pyranol' caps from 30 - 50 uFs too, which I've hoarded for power supplies. I found other large caps by Sangamo , CDE, and Micamold, but only 2 or 3 of those guys. I've got a rather large storage container on a small dolly with pio bath tub caps that are fine between tube stages, and even have those mounting tabs for 2 screws. By the way, I have turned in a number of mil spec leaker caps to hazardous waste disposal. Leaks caused mostly by trauma, (dropped on the floor, etc) and cheap paint letting rust at the scratched marks in paint... Incidentally, I replaced all the small but many rubber sealed caps, having a few leakers, with small hermetically sealed Mil-Spec caps instead in my Sansui 1000A. Still plays very nicely, approx 30 years later. Thanks for reading and very, very, good luck with your projects!!
Good, certainly
cheap, ehhhhhh noooooo
Ward de Ceuninck is a professor at Hasselt University and knows his stuff so you get an amazing transformer, but well that quality comes at a price.
Disclaimer: I have no involvement in his company but studied and worked for some years in the same building as him and coffee breaks could get interesting when he started talking about these kind of things
I like the mounting holes. No big metal washers and rubber disk. Just put a spacer under them or a piece of rubber mat and bolt them to the chassis.
There should be two rubber mats, one for top of transformer and one for bottom. They protect winding from metal base and top big washer and spread the mounting force.
I fired up one of the Toroidy OPT's in a prototype UNSET board. I was running it on My Fluke 407D power supply which struggles to power one channel with it's current meter pegged.
I got the amp up and running with a 3K ohm Transcendar OPT feeding a 4 ohm load on it's 8 ohm tap to reflect a 1.5K load, so I stuffed the board with the biggest fattest sweep tube in the box, a 36LW6. Once I was convinced that nothing was going to blow up, I swapped in the Toroidy OPT.
I set the B+ at 450 volts, and the bias at 200 mA and gave the output dial on the audio generator a spin until I hit clipping...The 8903 read 34 watts at 5% THD. Cranking up the current until the Fluke was on the edge of convulsions and turning up the B+ to 500 volts brought 43 watts at 2.4% THD. Turning down the drive to 1 watt brought a red glow from the tube.....UH 500 volts, 300+ mA, yeah that's about 150 watts being burned in a "40 Watt" tube.
I tinkered with B+ and current to find the best compromise, and found that 450 volts and 280 mA will result in 0.22%THD at 100 mW, 0.32% THD at 1 W, and 0.65% at 10W. 35 watts brings 3.3% and 38 watts hits 5%. All testing was at 1KHz. Dialing the generator up to 20 KHz makes a small rise in THD, but dialing it down below 100 Hz makes UGLY.
The most power I could get at 20 Hz was 2 watts, and I had to reduce the current below 200 mA to get there, which kills the power at other frequencies. I could get about 10 watts at 40 Hz but the THD was in the 5% range and it looked like saturation. This may not be a problem with real speakers since their impedance tends to rise in the 40 to 100 Hz region.
The poor LF could be related to the old Fluke, and I did not try my usual big fat cap across it's output.
The single tube breadboard is not up to driving a 1.5K load, so I need to make one with 2 or 3 tubes per channel. I am reluctant to test this with my BIG power supply since it has demonstrated its ability to really blow stuff up.
I really want to hear music played through a stereo amp using these OPT's, but that must wait until Sherri is not home.....Tuesday or Thursday.
I got the amp up and running with a 3K ohm Transcendar OPT feeding a 4 ohm load on it's 8 ohm tap to reflect a 1.5K load, so I stuffed the board with the biggest fattest sweep tube in the box, a 36LW6. Once I was convinced that nothing was going to blow up, I swapped in the Toroidy OPT.
I set the B+ at 450 volts, and the bias at 200 mA and gave the output dial on the audio generator a spin until I hit clipping...The 8903 read 34 watts at 5% THD. Cranking up the current until the Fluke was on the edge of convulsions and turning up the B+ to 500 volts brought 43 watts at 2.4% THD. Turning down the drive to 1 watt brought a red glow from the tube.....UH 500 volts, 300+ mA, yeah that's about 150 watts being burned in a "40 Watt" tube.
I tinkered with B+ and current to find the best compromise, and found that 450 volts and 280 mA will result in 0.22%THD at 100 mW, 0.32% THD at 1 W, and 0.65% at 10W. 35 watts brings 3.3% and 38 watts hits 5%. All testing was at 1KHz. Dialing the generator up to 20 KHz makes a small rise in THD, but dialing it down below 100 Hz makes UGLY.
The most power I could get at 20 Hz was 2 watts, and I had to reduce the current below 200 mA to get there, which kills the power at other frequencies. I could get about 10 watts at 40 Hz but the THD was in the 5% range and it looked like saturation. This may not be a problem with real speakers since their impedance tends to rise in the 40 to 100 Hz region.
The poor LF could be related to the old Fluke, and I did not try my usual big fat cap across it's output.
The single tube breadboard is not up to driving a 1.5K load, so I need to make one with 2 or 3 tubes per channel. I am reluctant to test this with my BIG power supply since it has demonstrated its ability to really blow stuff up.
I really want to hear music played through a stereo amp using these OPT's, but that must wait until Sherri is not home.....Tuesday or Thursday.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.