SET amp owners thread

[Norway]

 

[AMR / iFi audio]

View attachment 95141

I love this idea, but there are not many commercial products like that. For bass, you can even use clas D amps that will be integrated into the loudspeaker for super clean looks.

 

[Norway]

I love this idea, but there are not many commercial products like that. For bass, you can even use clas D amps that will be integrated into the loudspeaker for super clean looks.

No i think the F4 is the only One I know off and it’s not really a commercial product as it’s no longer available.

 

[ihmeyers]

Hope this isn't off topic.

I just recently purchased a pair of Antique Sound Lab 845 amps for use in a bedroom system. They were a little rough when I got them but I had some parts switched out (using some AN resistors and AN jacks and binding posts) and bought good tubes. Can I swap out an EL51 or F2A for the 6L6 tube in each amp? I've never heard of anyone doing that but I know it works in The Lampi TRP so it has to be possible at least in theory.

Thanks very much.

 

[AMR / iFi audio]

No i think the F4 is the only One I know off and it’s not really a commercial product as it’s no longer available.

By commercial products, I meant passive speakers with active bass modules. Pass F4 is only available as a DIY project now.

Hope this isn't off topic.

I just recently purchased a pair of Antique Sound Lab 845 amps for use in a bedroom system. They were a little rough when I got them but I had some parts switched out (using some AN resistors and AN jacks and binding posts) and bought good tubes. Can I swap out an EL51 or F2A for the 6L6 tube in each amp? I've never heard of anyone doing that but I know it works in The Lampi TRP so it has to be possible at least in theory.

Thanks very much.

F2a and EL51 use the same heaters 6,3V around 2A, so that is okay. But they are using different pinouts and sockets. You would need adapters, that is one thing. One of them is a tetrode and the other one is a pentode. Two different types of tubes. Another thing is an operating point, Lampizator builds its DACs in a special way to accommodate very different tubes. It's probably not the case with your amplifier.
So, no, you can't use them as replacements.

 

[bonzo75]

I am now in dialog with Werner regarding ordering one… I understand from him that it comes av a 3-way network 500hz and 8-10 kHz for a ultra HF unit!? Is 10 kHz the right point on my 288G? I have both a JBL 2404 and Fostex A500.
Another point is that his filters can be bi-wired/bi-amp(filter part for the 515 are separated from 288). Considering to use my First Watt F4s for the 817, letting the 300d SE drive both the 288+HF and also the F4s working the 817. Nelson promotes this idea in the F4 manual, Werner thinks it’s a bad idea but doable… anyone that has experimented with the F4s in this direction ?

Hi, I personally think it is a bad idea to use first watt on altecs. Well do it, but do give a simple crossover a try first going 300 SE throughout.

 

[godofwealth]

Just bought a pair of Cary 300B SET mono blocks with Western Electric 300Bs. Sound gorgeous with my Quad 57s (which remember were originally designed for the Quad II amps that produced 12 watts or so). But, I’m looking for high efficiency speakers, since everything I have at home is fairly low efficiency. Would love to get some recommendations for the gurus on this thread.

 

[Joao@altheamusica]

Just bought a pair of Cary 300B SET mono blocks with Western Electric 300Bs. Sound gorgeous with my Quad 57s (which remember were originally designed for the Quad II amps that produced 12 watts or so). But, I’m looking for high efficiency speakers, since everything I have at home is fairly low efficiency. Would love to get some recommendations for the gurus on this thread.

View attachment 95362

The biggest mistake in the Cary amps is that the first capacitor direct after the rectifier tube is too high - especially when using a 274a rectiver. It should be lowered to my opinion.

 

[Atmasphere]

The biggest mistake in the Cary amps is that the first capacitor direct after the rectifier tube is too high - especially when using a 274a rectiver. It should be lowered to my opinion.

Does it have a tendency to cause the rectifier tube to fail?

 

[cal3713]

View attachment 95141 Considering to use my First Watt F4s for the 817, letting the 300d SE drive both the 288+HF and also the F4s working the 817. Nelson promotes this idea in the F4 manual, Werner thinks it’s a bad idea but doable… anyone that has experimented with the F4s in this direction ?

I originally built my F4 for exactly this purpose... Coincident 300b Frankenstein monos driving the tweeter and midrange of my Coincident PREs, and also an F4 that then drove the speakers' separate bass modules.

The 300bs didn't really have enough power for this speaker (I upgraded from another more efficient Coincident design) and I was trying to lighten the load to save an amplifier that I really loved. In the end I lost a lot of coherency and didn't feel like I really gained anything substantial on the top end either. Then I tried running the F4s full range and was shocked to find that I actually preferred the F4s. Eventually I sold my beloved 300b monoblocks and put together full F4 monoblocks with top end parts and hugely overbuilt external power supplies.

 

[Carlos269]

I originally built my F4 for exactly this purpose... Coincident 300b Frankenstein monos driving the tweeter and midrange of my Coincident PREs, and also an F4 that then drove the speakers' separate bass modules.

The 300bs didn't really have enough power for this speaker (I upgraded from another more efficient Coincident design) and I was trying to lighten the load to save an amplifier that I really loved. In the end I lost a lot of coherency and didn't feel like I really gained anything substantial on the top end either. Then I tried running the F4s full range and was shocked to find that I actually preferred the F4s. Eventually I sold my beloved 300b monoblocks and put together full F4 monoblocks with top end parts and hugely overbuilt external power supplies.

I have also been surprised with my F2J amp, it really gives me almost, if not all, of what I get from SET amps. I use a 26 DHT preamp to drive the F2J and wow, SET sound with solid bass. I also have a M2X amp that sounds very, very good, and an F5 which sounds great after an hour of warmup. The First Watt designs can make a good alternative to flea-power SET amps and come in a number of flavors.

 

[Fishfood]

I have also been surprised with my F2J amp, it really gives me almost, if not all, of what I get from SET amps. I use a 26 DHT preamp to drive the F2J and wow, SET sound with solid bass. I also has a M2X amp that sounds very, very good, and an F5 which sounds great after an hour of warmup. The First Watt designs can make a good alternative to flea-power SET amps and come in a number of flavors.

I have a SET Amp (8WPC 300B) but am looking for exactly what you are talking about. The speakers are 96db 12" bass reflex studio monitors (Mitsubishi Diatones). Which First Watt amp is appropriate? I have been thinking about the Pass XA-25 but maybe a First Watt is more appropriate?

 

[Norway]

I originally built my F4 for exactly this purpose... Coincident 300b Frankenstein monos driving the tweeter and midrange of my Coincident PREs, and also an F4 that then drove the speakers' separate bass modules.

The 300bs didn't really have enough power for this speaker (I upgraded from another more efficient Coincident design) and I was trying to lighten the load to save an amplifier that I really loved. In the end I lost a lot of coherency and didn't feel like I really gained anything substantial on the top end either. Then I tried running the F4s full range and was shocked to find that I actually preferred the F4s. Eventually I sold my beloved 300b monoblocks and put together full F4 monoblocks with top end parts and hugely overbuilt external power supplies.

I have had some more input from Werner Jagusch who at this moment are building new crossovers for my Altecs. I suggested for him to incorporate the F4s into the filter design combining them with a SE 300b. His reply/experience is that, yes you can do this but you gain little to nothing at the cost of coherency.

 

[bonzo75]

I have had some more input from Werner Jagusch who at this moment are building new crossovers for my Altecs. I suggested for him to incorporate the F4s into the filter design combining them with a SE 300b. His reply/experience is that, yes you can do this but you gain little to nothing at the cost of coherency.

I am not sure why you insist on F4 without trying both. At least give the only 300b a try. Altecs do not require SS power to drive the woofers. Often this works against it, reducing bass by gripping too much. Werner is not expensive so you can try both. F4s will work differently with non-Altec woofers. I can't speak for F4 particularly but SS amps with grip have negative effects on Altec. So not sure how much grip F4 has.

 

[Carlos269]

I have a SET Amp (8WPC 300B) but am looking for exactly what you are talking about. The speakers are 96db 12" bass reflex studio monitors (Mitsubishi Diatones). Which First Watt amp is appropriate? I have been thinking about the Pass XA-25 but maybe a First Watt is more appropriate?

The First Watt amps all bring a little something different to the table. If I was in your position, I would give the F2J amp a listen with the Diatones.

 

[carolus]

View attachment 95141

... one quid:
From left channel mid/high (its a high pas filter) via F4 amp to left channel woofer & filter in low pas ... correct ?

 

[morricab]

I am not sure why you insist on F4 without trying both. At least give the only 300b a try. Altecs do not require SS power to drive the woofers. Often this works against it, reducing bass by gripping too much. Werner is not expensive so you can try both. F4s will work differently with non-Altec woofers. I can't speak for F4 particularly but SS amps with grip have negative effects on Altec. So not sure how much grip F4 has.

Depends if the SS amp has negative feedback on the output stage (or global). If the damping factor is too high then low Qts woofers all lose too much bass (even horn loaded). Horn loaded low Qts woofers like little to no damping from the amp...as they are already quite well damped. If the F4 is feedback free then the output impedance may not be all that low and there is a chance for decent bass then.

 

[bonzo75]

Depends if the SS amp has negative feedback on the output stage (or global). If the damping factor is too high then low Qts woofers all lose too much bass (even horn loaded). Horn loaded low Qts woofers like little to no damping from the amp...as they are already quite well damped. If the F4 is feedback free then the output impedance may not be all that low and there is a chance for decent bass then.

Yes I don't know what the output impedance and damping factor of F4 is, and how it compares to the 300b that he has. But surely, best thing for him is to listen for himself with both crossovers as it is not expensive. Right now he seems set on this biamping theory of using 300b on midrange and SS to drive 15 inch woofers.

 

[morricab]

Yes I don't know what the output impedance and damping factor of F4 is, and how it compares to the 300b that he has. But surely, best thing for him is to listen for himself with both crossovers as it is not expensive. Right now he seems set on this biamping theory of using 300b on midrange and SS to drive 15 inch woofers.

Yes, nothing better than good old experience...

 

[Fishfood]

The First Watt amps all bring a little something different to the table. If I was in your position, I would give the F2J amp a listen with the Diatones.

Thanks for the advice. Now I just have to find one of those rarities!