SET amp owners thread

cjfrbw

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bonzo75

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bazelio

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What is "this"? It was a general question. I'd like to hear it driving Jeffrey Jackson's horn creations.
 

morricab

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I have heard rhe Found Music Blade amp in silver a few times on Daedalus speakers. I have an idea what sound it gives. What do I gain or loose wirh a more true set amp on my PAP trio 15 horn. Below is a snip about the amp.

The Blade is a pentode amp, run in Single Ended Ultra Linear Push Pull. 28 watts with normal line input. A mouthful!

SET is Single Ended Triode, which I have made many of in the form of 45 and 2A3 amps. The Blade was a departure from this, and gave superior results to the SET in many ways for multi driver speakers and for speakers of lower efficiency.
How can this blade be Single ended and push/pull?
 
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morricab

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For such speakers I prefer more headroom, like Kronzilla or Jadis or Allnic A6000. In slightly lower watt SETs Lamms and Silvercore 833c (20w, easy budget) seem to have good drive. I am now looking at sub-7w category with maximum pushpull being 12w EL84 or a parallel 2a3.
I am having quite good results with my WLM Minueta on my mid/high horn (5 watts PP EL84 in class A triode mode). The Audio Note Oto SE Sig would also be an interesting one to try (but SEP not PP). I still want to see what a good 2A3 or 45 amp will do on the horns. I would try the SEP Mastersound but right now it’s too noisy...will tube roll to see if it improves.
 

bonzo75

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What is "this"? It was a general question. I'd like to hear it driving Jeffrey Jackson's horn creations.

Oh sorry I thought you were talking in the Daedulus context. I now see you were talking in the broader context of the thread
 
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cjfrbw

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I modified my little el cheapo Chinese SET ($250 ebay years ago) with wire wound resistors, upgraded caps, and tube adapters to run 6sl7 and 6b4g Svetlana tubes. Anode dissipation is 19 watts @ B plus of 295v with a Marconi 5Z3 rectifier, which comes out to about 4 watts of audio power per channel. It will also run 300b at about the same power, about 4-5 watts.

Using it exclusively in the 300-7Khz active crossover midband with the big BG 75 ribbons, the tiny Japanese transformers are an advantage because there is less metal for the signal to pass through, no lower four octaves or upper octave and a half to worry about.

The Svetlana 6b4g are still beneath the audiophile radar (province of DIY crowd mostly), can be had for $60 a pair, ruggedly built, and sound amazing. I have some 6a4g indirectly heated NOS Sylvania green leaf tubes to try as well @ $56/pair.

I am having difficulty conceptualizing whether anything higher up the food chain would sound much better. My other little ebay home cobbled 45 amp (also with upgraded caps and wirewound resistors) sounds incredible as well with ordinary Philco 45 tubes.
 

morricab

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I modified my little el cheapo Chinese SET ($250 ebay years ago) with wire wound resistors, upgraded caps, and tube adapters to run 6sl7 and 6b4g Svetlana tubes. Anode dissipation is 19 watts @ B plus of 295v with a Marconi 5Z3 rectifier, which comes out to about 4 watts of audio power per channel. It will also run 300b at about the same power, about 4-5 watts.

Using it exclusively in the 300-7Khz active crossover midband with the big BG 75 ribbons, the tiny Japanese transformers are an advantage because there is less metal for the signal to pass through, no lower four octaves or upper octave and a half to worry about.

The Svetlana 6b4g are still beneath the audiophile radar (province of DIY crowd mostly), can be had for $60 a pair, ruggedly built, and sound amazing. I have some 6a4g indirectly heated NOS Sylvania green leaf tubes to try as well @ $56/pair.

I am having difficulty conceptualizing whether anything higher up the food chain would sound much better. My other little ebay home cobbled 45 amp (also with upgraded caps and wirewound resistors) sounds incredible as well with ordinary Philco 45 tubes.
4 watts on the BG driver is enough? I ran a 30 watt KR VA350i on mine (shorter one than yours) back in the day and that was super but 4 seems a wee bit too few.
 

cjfrbw

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4 watts on the BG driver is enough? I ran a 30 watt KR VA350i on mine (shorter one than yours) back in the day and that was super but 4 seems a wee bit too few.
The lowest power tube I have tried in this amp (before I modified it a bit) was the 1.3 watt 182b tube (5 volt cathode 45 type). It sounded wonderful, and did not give any indication it was suffering at the 300Hz-7khz bandwidth, even playing loud. 45 works fine@1.6 watts. 4 watts seems more than enough and even sounds powerful. The 20 watt VFET and 50 watt Wavac are monster amps with these ribbons.

As I have stated before, I have no knowledge of why these 75 inch ribbons are so efficient. They were purchased as factory close out when BG was closed. They must have been a batch of newer, high efficiency types with stronger magnets, possibly made for Wisdom Audio.

I can find no information on any BG ribbons that state an efficiency otherwise higher than 88-89 db or so. I estimate that the ribbons that I have in hand to have an effective line source/dipole efficiency of 94-96 db at least.

The bass panel of the Analysis Epsilon run by itself full range I estimate has an efficiency of about 88 db, but requires a bit more power. The bass panel of Analysis Epsilon running full range, however, works fine with 20 watt class A VFET (probably 30 watts at the 4 ohm impedance).

As a result, it has been real treat playing around with these flea power amps that I had only used as tweeter amps before, and they sound great on the big midrange ribbons. That makes them a novel experience in my own system in this midrange frequency range.

Flea powered amps and an efficient ribbon make a very nice combo. However, these particular BG 75 ribbons appear to be limited production because provenance is inaccessible from what I have explored. It was a cool easter egg, because that wasn't what I expected when I bought them. They also image hugely in all dimensions, including the vertical. This was one of those audiophile luck-outs to balance all of the boners.
 
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morricab

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The lowest power tube I have tried in this amp (before I modified it a bit) was the 1.3 watt 182b tube (5 volt cathode 45 type). It sounded wonderful, and did not give any indication it was suffering at the 300Hz-7khz bandwidth, even playing loud. 45 works fine@1.6 watts. 4 watts seems more than enough and even sounds powerful. The 20 watt VFET and 50 watt Wavac are monster amps with these ribbons.

As I have stated before, I have no knowledge of why these 75 inch ribbons are so efficient. They were purchased as factory close out when BG was closed. They must have been a batch of newer, high efficiency types with stronger magnets, possibly made for Wisdom Audio.

I can find no information on any BG ribbons that state an efficiency otherwise higher than 88-89 db or so. I estimate that the ribbons that I have in hand to have an effective line source/dipole efficiency of 94-96 db at least.

The bass panel of the Analysis Epsilon run by itself full range I estimate has an efficiency of about 88 db, but requires a bit more power. The bass panel of Analysis Epsilon running full range, however, works fine with 20 watt class A VFET (probably 30 watts at the 4 ohm efficiency).

As a result, it has been real treat playing around with these flea power amps that I had only used as tweeter amps before, and they sound great on the big midrange ribbons. That makes them a novel experience in my own system in this midrange frequency range.

Flea powered amps and an efficient ribbon make a very nice combo. However, these particular BG 75 ribbons appear to be limited production because provenance is inaccessible from what I have explored. It was a cool easter egg, because that wasn't what I expected when I bought them. They also image hugely in all dimensions, including the vertical. This was one of those audiophile luck-outs to balance all of the boners.
The only planars I know of with that kind of efficiency are using Nd magnets. I can’t imagine getting that much sensitivity with normal ferrite magnets unless they are huge (for example a Nd based compression driver might weigh 2-3kg but the equivalent ferrite driver 7+kg). Maybe BG slipped some Nd magnets in there as an experiment? Otherwise, you can’t really cheat physics. The only other thing I can think of is that their original design benefitted from serious redesign to optimize the magnetic fields. Whatever, it works and you can benefit from glorious low watt tubes on a very transparent driver.
 

morricab

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The lowest power tube I have tried in this amp (before I modified it a bit) was the 1.3 watt 182b tube (5 volt cathode 45 type). It sounded wonderful, and did not give any indication it was suffering at the 300Hz-7khz bandwidth, even playing loud. 45 works fine@1.6 watts. 4 watts seems more than enough and even sounds powerful. The 20 watt VFET and 50 watt Wavac are monster amps with these ribbons.

As I have stated before, I have no knowledge of why these 75 inch ribbons are so efficient. They were purchased as factory close out when BG was closed. They must have been a batch of newer, high efficiency types with stronger magnets, possibly made for Wisdom Audio.

I can find no information on any BG ribbons that state an efficiency otherwise higher than 88-89 db or so. I estimate that the ribbons that I have in hand to have an effective line source/dipole efficiency of 94-96 db at least.

The bass panel of the Analysis Epsilon run by itself full range I estimate has an efficiency of about 88 db, but requires a bit more power. The bass panel of Analysis Epsilon running full range, however, works fine with 20 watt class A VFET (probably 30 watts at the 4 ohm efficiency).

As a result, it has been real treat playing around with these flea power amps that I had only used as tweeter amps before, and they sound great on the big midrange ribbons. That makes them a novel experience in my own system in this midrange frequency range.

Flea powered amps and an efficient ribbon make a very nice combo. However, these particular BG 75 ribbons appear to be limited production because provenance is inaccessible from what I have explored. It was a cool easter egg, because that wasn't what I expected when I bought them. They also image hugely in all dimensions, including the vertical. This was one of those audiophile luck-outs to balance all of the boners.
I once visited the Piega factory when I was reviewing a speaker of theirs and their coaxial planar speaker, which uses very strong Nd magnets was capable of 104db without a horn! I would have paid good money for a complete speaker using that driver with over 100db sensitivity! Piega, alas, is too conservative to go that way...too obsessed with flat frequency response.
 

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With analysis omega we found a big difference between NAT 60w and the 120 watt transmitter. The sound really opened up with the latter, otherwise it stayed more compressed and towards the speaker, strained.
 

morricab

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With analysis omega we found a big difference between NAT 60w and the 120 watt transmitter. The sound really opened up with the latter, otherwise it stayed more compressed and towards the speaker, strained.
Analysis speakers are really around 86 dB or so. Would be interesting to hear 20-30 watts on the Alsyvox.
 

cjfrbw

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The midrange/high ribbon on my Analysis Epsilon is not particularly efficient. It is less efficient than the bass panel and needs both power and current @ 2.5 ohms. It does quite well with the 50 watt Wavac (or First Watt M2 @ 25 class A watts) played through an impedance matching transformer to bring impedance up to 8 ohms. The BG 75 by contrast does not need much in the way of power or current, and is native flat 6 ohm impedance.

The overall efficiency of Analysis Epsilon when matched down with a passive crossover is stated at 86 db. However, the bass panel is more efficient and easier to drive than the midrange ribbon and is not the limiting agent.

The bass panel of Analysis Epsilon is a pleasing full range speaker in its own right and I play it from time to time as a 'simple' crossover-less system when I don't want to mess with the more complex system.
 
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morricab

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The midrange/high ribbon on my Analysis Epsilon is not particularly efficient. It is less efficient than the bass panel and needs both power and current @ 2.5 ohms. It does quite well with the 50 watt Wavac (or First Watt M2 @ 25 class A watts) played through an impedance matching transformer to bring impedance up to 8 ohms. The BG 75 by contrast does not need much in the way of power or current, and is native flat 6 ohm impedance.

The overall efficiency of Analysis Epsilon when matched down with a passive crossover is stated at 86 db. However, the bass panel is more efficient and easier to drive than the midrange ribbon and is not the limiting agent.

The bass panel of Analysis Epsilon is a pleasing full range speaker in its own right and I play it from time to time as a 'simple' crossover-less system when I don't want to mess with the more complex system.
I used to have an F25, To be honest, I was never in love with this crossover. This minidsp with external dacs, at least for digital, is a better sounding solution.
 

cjfrbw

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Yes, you didn't seem to like F25 at all.

I am happy with it and don't find it to have any particular negative character. When fed the full range signal from the Allnic DHT preamp, the resulting outputs produce exemplary result, so it works here. It transmits the DHT character quite well.

Anecdotally, I have found that interleaving tube and solid state stages seems to work better than all tube or all solid state. Whether that would work anywhere else, I don't know.
 

morricab

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Yes, you didn't seem to like F25 at all.

I am happy with it and don't find it to have any particular negative character. When fed the full range signal from the Allnic DHT preamp, the resulting outputs produce exemplary result, so it works here. It transmits the DHT character quite well.

Anecdotally, I have found that interleaving tube and solid state stages seems to work better than all tube or all solid state. Whether that would work anywhere else, I don't know.
I would not say that. Just not enough to keep it.
 

Kingrex

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On Audionirvana there is a guy posting for Lansing Audio gear. SET amp is his push. On the site they sell oak 12 cell multi cell horns for $1400 or so. That is a deal if they are done well. Made in Japan.
 

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