SET amp owners thread

[the sound of Tao]

Equipment contributing to that "being there" environment. I had an amp that filled the room with smoke once. It would have been more convincing if the ballast resistors were formed from tobacco or hemp. The younger people here may not know what I reefer to.

and us of the older one’s perhaps once knew but have now just forgot I have some (decommissioned) Quicksilver 8417 monos that used to occasionally glow just like that time bubble when Arnie the Terminator Schwartzenugenuger used to travel back through time with.

 

[ketcham]

In reference to the Allnic M311 SET and M2500 push-pull, both with tube rectifiers, I purposely purchased the PX25 version of both amps. Two reasons. I wanted hear the characteristics of each amp while keeping the tubes as uniform as able. The M311 has an interchange transformer and less quantity of tubes. Both however are dead silent with your hear to the speaker. As mentioned previously I own the Daedalus Zeus at 99 dB efficiency and has two 10" drivers. Either amp design drives the Daedalus without issue. The bass is something truly amazing. The second reason is I prefer the sonic characteristics of the PX25 - more weighty bass, and a sublime revealing midrange. While the PX25 is 7.5 watts and 20W respectively, the lower wattage does not sacrifice in my system.

Of interest, replacing my 1936 OSRAM PX25 with the KRON modern PX25 really really improved the M2500 in both clarity and dynamics. I since shipped them off to a friend out on the East Coast because he has the Apollo muse and will be purchasing the 11's. He placed these amps on Proac D48R, 90 dB, 4 ohm speakers. "Those amps are current heavy and there is headroom to spare." Impressive! My recommendation in this situation would have been the 100W continuous Pentode KT150s, certainly not the PX25s! This insight is appreciated. The M2500 maintains the micro detailing, texture overall finesse across the midrange SET designs is known for while improving the dynamics, slam factor and extended and focused bass.

300b - have more power: M311 is 10 watt SET, and M2500 is 30W continuous triode push-pull. There are and certainly will be a large variety of modern production tubes. 300b often have better resale value. I purchase for long term investment. Resale value has never been my focus.

(Disclaimer, I am an Allnic dealer after 12 years of being an owner of a large portion of their product line. I am very familiar with the brand overall and my focus here is to provide information. Don Corby of Corby Audio and David Beetles of Hammertone Audio are also highly recommended)

 

[Joao@altheamusica]

Hi I do not know technically. But if you listen, and play something complex, you will not get as much control over each instrument with JJ (or TJ, electroharmonix, and full) as KR or Elrog. When I say control, it is mist each instrument holding its own line steadily from star to finish, plus the separation between the instruments will be greater

OK, I agree that's a good description you wrote... short description: technically it has to do with damping factor (the ratio of the rated impedance of the loudspeaker to the source impedance DF= Zload / Zsource). In Zsource the plate resistance of the output tube is involved...

 

[Tuckia]

In reference to the Allnic M311 SET and M2500 push-pull, both with tube rectifiers, I purposely purchased the PX25 version of both amps. Two reasons. I wanted hear the characteristics of each amp while keeping the tubes as uniform as able. The M311 has an interchange transformer and less quantity of tubes. Both however are dead silent with your hear to the speaker. As mentioned previously I own the Daedalus Zeus at 99 dB efficiency and has two 10" drivers. Either amp design drives the Daedalus without issue. The bass is something truly amazing. The second reason is I prefer the sonic characteristics of the PX25 - more weighty bass, and a sublime revealing midrange. While the PX25 is 7.5 watts and 20W respectively, the lower wattage does not sacrifice in my system.

Of interest, replacing my 1936 OSRAM PX25 with the KRON modern PX25 really really improved the M2500 in both clarity and dynamics. I since shipped them off to a friend out on the East Coast because he has the Apollo muse and will be purchasing the 11's. He placed these amps on Proac D48R, 90 dB, 4 ohm speakers. "Those amps are current heavy and there is headroom to spare." Impressive! My recommendation in this situation would have been the 100W continuous Pentode KT150s, certainly not the PX25s! This insight is appreciated. The M2500 maintains the micro detailing, texture overall finesse across the midrange SET designs is known for while improving the dynamics, slam factor and extended and focused bass.

300b - have more power: M311 is 10 watt SET, and M2500 is 30W continuous triode push-pull. There are and certainly will be a large variety of modern production tubes. 300b often have better resale value. I purchase for long term investment. Resale value has never been my focus.

(Disclaimer, I am an Allnic dealer after 12 years of being an owner of a large portion of their product line. I am very familiar with the brand overall and my focus here is to provide information. Don Corby of Corby Audio and David Beetles of Hammertone Audio are also highly recommended)

Ketcham,

Thank you for introducing these products which we previously mentioned in this thread. Your perspectives are most relevant in my, and possibly others ongoing search. I will PM you shortly.

Regards,
Greg

 

[Tuckia]

OK, I agree that's a good description you wrote... short description: technically it has to do with damping factor (the ratio of the rated impedance of the loudspeaker to the source impedance DF= Zload / Zsource). In Zsource the plate resistance of the output tube is involved...

Are you suggesting that the output impedance of KR tubes is non-standard? Different from the other manufacturers mentioned here to achieve this characteristic? This explanation would apply to individual situations of amp/speaker interfacing and not a broad characteristic of KR tube sound.

 

[Joao@altheamusica]

You have some feedback from us now. Can you comment on these thoughts? Can you add your own thoughts and observations?
Thanks.

Technical short description: see above response #863
My thoughts and observations: I designed so many tube amps (SE & PP) and sonically I left the 300B camp after 3 years playing with 300B, I prefer more 45, RE604, AD1 and the matching speakers...
But in all those designs I made the experience that the driver tube is more imprtant... next is the quality of the transformers (in signal path and power supply), a low impedance ciruit and a stable power supply; a stable psu is very important.
And last but not least: what the sources do not deliver to the amplifier is lost, cannot be played back. The signal conversion - from the source (i.e. mchanical from analog sources and the speakers - for me is number one!

 

[bonzo75]

Technical short description: see above response #863
My thoughts and observations: I designed so many tube amps (SE & PP) and sonically I left the 300B camp after 3 years playing with 300B, I prefer more 45, RE604, AD1 and the matching speakers...
But in all those designs I made the experience that the driver tube is more imprtant... next is the quality of the transformers (in signal path and power supply), a low impedance ciruit and a stable power supply; a stable psu is very important.
And last but not least: what the sources do not deliver to the amplifier is lost, cannot be played back. The signal conversion - from the source (i.e. mchanical from analog sources and the speakers - for me is number one!

Hi, no experience with RE604. What is it like compared to the 45 or a 2a3, and where do you put AD1 in that regard? I ask from the point of view of listening to both small chamber and large orchestra, for easy to drive, simple crossover, 2 or 3 way dual woofer front loaded horns with say Altec 515b or JBL 2220b as Midbass, and Altec or TAD or Radian beryllium mids. In most cases around 110db, 8 ohm impedance, first or second order crossover

 

[Joao@altheamusica]

Are you suggesting that the output impedance of KR tubes is non-standard? Different from the other manufacturers mentioned here to achieve this characteristic? This explanation would apply to individual situations of amp/speaker interfacing and not a broad characteristic of KR tube sound.

Measure the tubes! How many 300Bs have you measured? There was an article in old Glass Audio magazines about this topic... worth to read.
I have imported the first tubes from Kron when they have been sold under the brand Vaic Valve and I met Alesa Vaic (the inventor of those tubes - EML is based on the same design) so I have some more insight views...

I don't suggesting anything, I desribed technical truth but the plate resistance is not only the reason... but you are correct that individual situations of amp/speaker interfacing is the thing. Next we have the mechanical structure / composition and used materials of the tubes... if anyone prefers one brand over another brand I have no problem with it, so enjoy your tube rolling.

 

[Joao@altheamusica]

Hi, no experience with RE604. What is it like compared to the 45 or a 2a3, and where do you put AD1 in that regard? I ask from the point of view of listening to both small chamber and large orchestra, for easy to drive, simple crossover, 2 or 3 way dual woofer front loaded horns with say Altec 515b or JBL 2220b as Midbass, and Altec or TAD or Radian beryllium mids. In most cases around 110db, 8 ohm impedance, first or second order crossover

Very good questios and not so easy to answer because, like you know, its a matter of taste. My answer in short:
2A3 I prefer over every 300B because it's easier to drive and the sound is more wide band and warmer... (good with Tamura opt.)
RE604 and 45 are very similar, very detailled and clear sound, I'd like to say for a soprano they are Maria Callas.
AD1 is as well very detailled like a RE604 / 45 but has it's pro is more in the lower region, very pitty bass but the high frequency is more darker in timbre (compared to the 604/45) - she's alto voice... the AD1 derivate from EML is very good compared to the original.

My hornsystem uses a solid state for the bass driver, an AD1 or 604/45 for the mid range (I prefer the mostly AD1) and 604/45 for the high frequency. XO-frequencies are 250Hz and 2.5KHz.

I think it's a matter of taste what you choos but the output transformers must be best quality. Small chamber I think the 45 is the better choice and the AD1 for large scale orchestra - so why not 2 amplifiers for each music taste?

 

[bonzo75]

Yes, Allnic is making an AD1 as well.

So you will prefer AD1 over 2a3?

In transformers, you have experience with tamura, tango, Hashimoto?

What drivers are you using in the horn? I remember you liking phenolic, have you compared Gauss to JBL?

 

[Joao@altheamusica]

Yes, Allnic is making an AD1 as well.
So you will prefer AD1 over 2a3?
In transformers, you have experience with tamura, tango, Hashimoto?
What drivers are you using in the horn? I remember you liking phenolic, have you compared Gauss to JBL?

Short reply:
* yes I prefer AD1 over 2A3... 2A3 is, in my taste, an all-rounder and a very good entry into the world of DHT.
* Transformers:yes I have experience with the brands you name but Hashimoto is, as well spoken for me, a no go.
* yes I use phenolic drivers which are adapted for my horns and I prefer them because of the vocal tone with the timbre of voices.
haven't compared Gauss to JBL but I like the 24xx from JBL... then there are WE555, RCA etc.
With vintage drivers it's like with vintage tubes to find some good matching pairs.
TAD drivers are very good as well but in some horns they need a HF-driver aside...

If you like we can continue by PM because this will break the thread which is about SET amps. You should notice that this theme is very special and you entering a new world of music reproduction. You must restart and designing your system with metculousness - this will take many years of experience. You will not find finished systems, you have to build it by yourself... you are not allone....

 

[ketcham]

Joao - I considered the AD1 but opted for PX25. AD1 I hear the tubes are very difficult to source and the power output is roughly 1/3 300b and 1/2 that of PX25. Typically not an issue for horn speakers, which I do not own. Thank you for your interpretation of the AD1.

 

[bonzo75]

Short reply:
* yes I prefer AD1 over 2A3... 2A3 is, in my taste, an all-rounder and a very good entry into the world of DHT.
* Transformers:yes I have experience with the brands you name but Hashimoto is, as well spoken for me, a no go.
* yes I use phenolic drivers which are adapted for my horns and I prefer them because of the vocal tone with the timbre of voices.
haven't compared Gauss to JBL but I like the 24xx from JBL... then there are WE555, RCA etc.
With vintage drivers it's like with vintage tubes to find some good matching pairs.
TAD drivers are very good as well but in some horns they need a HF-driver aside...

If you like we can continue by PM because this will break the thread which is about SET amps. You should notice that this theme is very special and you entering a new world of music reproduction. You must restart and designing your system with metculousness - this will take many years of experience. You will not find finished systems, you have to build it by yourself... you are not allone....

Ah, I am going to build a speaker already built by someone else, but would like to play with amps around it. And then drivers

 

[christoph]

Short reply:
* yes I prefer AD1 over 2A3... 2A3 is, in my taste, an all-rounder and a very good entry into the world of DHT.
* Transformers:yes I have experience with the brands you name but Hashimoto is, as well spoken for me, a no go.
* yes I use phenolic drivers which are adapted for my horns and I prefer them because of the vocal tone with the timbre of voices.
haven't compared Gauss to JBL but I like the 24xx from JBL... then there are WE555, RCA etc.
With vintage drivers it's like with vintage tubes to find some good matching pairs.
TAD drivers are very good as well but in some horns they need a HF-driver aside...

If you like we can continue by PM because this will break the thread which is about SET amps. You should notice that this theme is very special and you entering a new world of music reproduction. You must restart and designing your system with metculousness - this will take many years of experience. You will not find finished systems, you have to build it by yourself... you are not allone....

Please not via PM.
This is too interesting to be kept from us!

 

[Joao@altheamusica]

Joao - I considered the AD1 but opted for PX25. AD1 I hear the tubes are very difficult to source and the power output is roughly 1/3 300b and 1/2 that of PX25. Typically not an issue for horn speakers, which I do not own. Thank you for your interpretation of the AD1.

PX25 is another interesting tube (so many types and so less time)... in comparison to 300B much easier to drive! A friend of mine (with WE22a & WE555 / WE 597 from Line Magnetics) owns several PX4 - yes less power but interesting as well, sonorous and nice midrange...

Another hint: pentodes in triode mode... have a look on older stuff used in radio stations or studio! EL84 as triode in SE delvers nice sound in upper frequencies Anyway, for some speakers we can use some of the tubes in push-pull - some will be surprised what sound quality comes out of the speakers....

 

[Joao@altheamusica]

Ah, I am going to build a speaker already built by someone else, but would like to play with amps around it. And then drivers

You're welcome and good luck

 

[bonzo75]

PX25 is another interesting tube (so many types and so less time)... in comparison to 300B much easier to drive! A friend of mine (with WE22a & WE555 / WE 597 from Line Magnetics) owns several PX4 - yes less power but interesting as well, sonorous and nice midrange...

Another hint: pentodes in triode mode... have a look on older stuff used in radio stations or studio! EL84 as triode in SE delvers nice sound in upper frequencies Anyway, for some speakers we can use some of the tubes in push-pull - some will be surprised what sound quality comes out of the speakers....

El84 is push pull is very good, agile mids and high frequencies, very nice tone.

 

[Joao@altheamusica]

Please not via PM.
This is too interesting to be kept from us!

Christoph, thank you for the flowers .... let's see what we can do and not to capture the thread....
BTW, am I correct that you are liveing in Liechtenstein? I'm residing in Switzerland at the Lake Constance... if you like we can meet us, listening music etc.

 

[bonzo75]

Christoph, thank you for the flowers .... let's see what we can do and not to capture the thread....
BTW, am I correct that you are liveing in Liechtenstein? I'm residing in Switzerland at the Lake Constance... if you like we can meet us, listening music etc.

Well if we are allowed to travel again I would love to come as well. Not sure what it is with the the Swiss and horns

 

[christoph]

Christoph, thank you for the flowers .... let's see what we can do and not to capture the thread....
BTW, am I correct that you are liveing in Liechtenstein? I'm residing in Switzerland at the Lake Constance... if you like we can meet us, listening music etc.

Yes, please