SETs and Horns

[ArnoFenn]

Agreed. I'd like to see more pictures AND more explanation of how the horn and amplifier combos were chosen and fit into the listening space.

In my case, I calculate the horn, the the building, listening and fine-tuning. After that, design the SET. building it and fine-tune in combination with the horns (a lot of listening and measuring over the years)

 

[Blue58]

Hello cal3713,

I don’t have a thread for the build and in all honesty would not build it again this way as it’s too expensive!

I noticed you use the Shiny Eyes pre and he makes a very nice 45 turbo amp using same outputs as mine and EML tubes too so you couldn’t go wrong with that one.

cheers
Blue58

 

[cal3713]

Hello cal3713,

I don’t have a thread for the build and in all honesty would not build it again this way as it’s too expensive!

I noticed you use the Shiny Eyes pre and he makes a very nice 45 turbo amp using same outputs as mine and EML tubes too so you couldn’t go wrong with that one.

cheers
Blue58

Thanks, yes, I love Radu's work. I just sent my pre back to him to have him make it into a dual mono design with separate power supplies for each channel. Was considering trying to build my own amps though. I've read a decent amount on diyaudio (mostly about pres), but a clean, dedicated build thread would still be useful.

 

[Atmasphere]

I'm considering buying horns and if so would be curious to try a 45-based amplifier.

If they are being honest, a type 45 based SET only makes about 0.75 watts. Keeping in mind that to get the most out of an SET you should not go past about 20-25% of full power, you would need an exceedingly high efficiency speaker to really use an amp with this tube properly- 105dB or greater. For that reason IMO/IME (Ihad a set of type 45 based SETs for quite s while) they are best suited for headphones.

 

[cal3713]

If they are being honest, a type 45 based SET only makes about 0.75 watts. Keeping in mind that to get the most out of an SET you should not go past about 20-25% of full power, you would need an exceedingly high efficiency speaker to really use an amp with this tube properly- 105dB or greater. For that reason IMO/IME (Ihad a set of type 45 based SETs for quite s while) they are best suited for headphones.

Thanks Ralph. The horns I'm looking at are 108, so I think 45s will work.

But like you say, I see plenty of people using more power even at that sensitivity level. Perhaps I'd still end up preferring my 25w First Watts...

 

[MarcelNL]

Hi there, new member here, I just signed up, especially for this thread!

I am currently 'ínto' infinite baffle front loaded horns, and like them a lot for what they IMO do best, produce a very natural and 'organic' sound. The trade-off is size, and therefore WAF.....Currently I'm working on a system based on the Klangfilm Bionor, measuring just over 2m by 2m.

Power for now comes, from a stock KL204a amp (F2A11 tube) and to me it's a very natural sounding combination with enough power to drive them loud with all sorts of music (ranging from anything between Schumann Lieder to Mika Vainio) without starting to sound awful. The Trionor comes in at an estimated 105+db/w/m, using three 13"fullranges and the JBL 2402 so almost no filtering needed.

not sure if these ARE the best but they sure are large; https://www.ebay.nl/itm/The-best-ho...049465?hash=item23ee405779:g:OHYAAOSw85tfQkF5

 

[guf]

If they are being honest, a type 45 based SET only makes about 0.75 watts. Keeping in mind that to get the most out of an SET you should not go past about 20-25% of full power, you would need an exceedingly high efficiency speaker to really use an amp with this tube properly- 105dB or greater. For that reason IMO/IME (Ihad a set of type 45 based SETs for quite s while) they are best suited for headphones.

Thanks Ralph. The horns I'm looking at are 108, so I think 45s will work.

But like you say, I see plenty of people using more power even at that sensitivity level. Perhaps I'd still end up preferring my 25w First Watts...

In my experience I liked the type 45 more than my first watts, and more than the 300b. Every time i try amps with more power it makes me miss my type 45. Well now i'm using a type 46.

Ralph maybe something was wrong with your 45? There is lots of great builders out there.

 

[petavgeris]

There has been a lot of enthusiasm expressed on WBF about SETs and horns. Some passionate advocacy in discussions might even cause an impression that there are only advantages to this type of systems, no drawbacks.

Hello!
Would just like to add my two cents on the topic.
Having manufactured already many SET designs, like phono preamplifiers, line preamplifiers, MC step up transformers and of course power amplifiers, all with custom manufactured iron in double c core fashion, with custom ferromagnetic alloys, custom shapes and sizes, hand-wound everything with my own hands (and not simply to my own standards, wound by a third party), I can declare that I am in the position to give a very thoughtful reply, carrying on my back more than 15 years of transformers designing, winding, manufacturing and of course testing.
Pay attention: I am not referring to commercially available units but only to creations that escape from the classic barriers that have to do with spatial and financial obstacles and constraints. The reason is the excessively high cost. All pure SET designs make use of large number of iron pieces. Several of my creations make use of enormously large number of iron pieces, while my recommendations for highest level audio machines require ridiculous, insane amounts of iron. Good SET and cheap are two contradictory aspects.
I am referring to the topology done right.

So apart from questions of practicality, such as size of horns, WAF and money to be invested, my questions are:

1. In which areas to SET/horn systems excel?

Every single area! No exceptions!

2. In which areas can they not even be matched by other types of systems?

Everything! No exceptions!

3. Are there any sonic drawbacks to SET/horn systems, in the sense that there are other system types that just can do certain things better?

Absolutely not!

4. How much money do you have to spend on an excellent SET/horn system? How much money do you have to spend on a good SET/horn system?

Entry level SET/horn combos would cost aprox. $50k, only for the amplifiers and speakers.
High quality SET/horn speaker combos definitely surpass the $100k mark.
For highest level of musical reproduction, $200-300k can very easily be reached and surpassed.

5. What about the question of the oft-mentioned horn colorations? Are they still a concern in modern horns? Are they a concern in vintage horns?

In high level designs there exists no coloration at all. In the designs that we are all experiencing at the various Hi-Fi shows around the globe, yes, coloration is a real issue, some times close to unbearable amounts of distortion. This does not mean that the concept / topology is to blame.

Hope all this helps...

 

[cal3713]

In my experience I liked the type 45 more than my first watts, and more than the 300b. Every time i try amps with more power it makes me miss my type 45. Well now i'm using a type 46.

Ralph maybe something was wrong with your 45? There is lots of great builders out there.

Can you write a bit about why you prefer the 46 to the 45? I see @Audiophile Bill is doing the same...

 

[Atmasphere]

Ralph maybe something was wrong with your 45? There is lots of great builders out there.

These amps were reputed to be built by a guy named Burgess who has a good reputation. Regardless, they obviously needed attention- I replaced the aging filter capacitors, and tested the circuit, doing as much as I could to linearize it and clean it up- they were a bit sloppy inside (after a while I began to doubt their origin story). They had great bandwidth; I ran a DC supply so they were also low hum. They sounded alright but I simply could not get them on a speaker that had enough efficiency. I tried a variety of coupling caps, and settled on a set of oil filled parts.

Ultimately I set them up for push-pull operation and went from 0.75watts to about 6 watts. I retained the same tube types RCA type 45s exclusively) and components. The new circuit was class A as well. It was even wider bandwidth and lower noise. It was also a lot more revealing (using headphones for that comparison, since on loudspeakers it wasn't fair to the SET version) so at that point I concluded that a lot of comments about how SET was so great over PP amps was really a red herring- the PP in the comparison probably had different power tubes (usually pentodes instead of DHTs) with feedback and likely not class A and the like. When you use the same power tubes and class of operation and no feedback and the same grounding techniques and component types and so on to level the playing field you start to see what's really going on. The other way I went around this was to create a small PP amp that only made 5 watts, using the idea that most SETs are compared to amps that have multiples of the SET power. Any of the SETs I've been able to get my hands on just don't seem to be as musical as that little 5 watt amp (and cost a lot more too). So coming at this from three different directions (if you include the OTLs I work with) I've yet to be convinced that SETs are really the panacea they're made out to be.

If I take a refurbished ST-70 I can see why people like SETs (PP amps that combine SE circuitry tend to have a prominent 5th harmonic due to algebraic summing of the quadratic and cubic nonlinearities). The same is true of most solid state amps (most of them don't use enough feedback and so are harsh and bright). Its so hard to hear everything that's out there and since spec sheets have been the Emperor's New Clothes for the last 60 years by ignoring certain hearing perceptual rules. We've all grown used to being lied to and simply having to audition the stuff in our homes. So I can't say I've heard everything, but I've heard a lot. I've even heard class D amps to which no SET I've ever seen/heard could hold a candle even on horn systems.

This has been and always will be about that first watt, which has to be sublimely correct. That is the thing that SETs can do well, but if you design with that in mind, its not the only way to crack that nut.

 

[MarcelNL]

At a friend's place I recently heard an exotic Telefunken Mesh tube crank out the sweetest 1 Watt (if that) or so I ever heard, then the tube died (it was a a rare one and the only one available at that time) and we continued listening to a 15$ class D amp with some tinkering done to the PSU. Both playing mono on 2 large baffles with 2 KL405 full range speakers each side so high efficiency. Bottom line was that the SE mesh tube sounded much more magical than the class D but the class D came a long way.

 

[Solypsa]

...
Having manufactured already many SET designs, like phono preamplifiers, line preamplifiers, MC step up transformers and of course power amplifiers, all with custom manufactured iron in double c core fashion, with custom ferromagnetic alloys, custom shapes and sizes, hand-wound everything with my own hands (and not simply to my own standards, wound by a third party), I can declare that I am in the position to give a very thoughtful reply, carrying on my back more than 15 years of transformers designing, winding, manufacturing and of course testing.
....

I for one would love to learn more about your projects. If you feel like sharing please do start a thread about them!

 

[cal3713]

I for one would love to learn more about your projects. If you feel like sharing please do start a thread about them!

Add me to the list.

 

[guf]

Can you write a bit about why you prefer the 46 to the 45? I see @Audiophile Bill is doing the same...

I'm not sure really I have been using a 45 for years. The past 3 months the 46. I tend to follow my heart. I read Thomas Mayers love for them. That's an influence. I respect him. I trust him. I use his gear. My experience with him, as a customer has been the best. He's very responsive. His build time was better than anyone I have every dealt with. His online presence is comendable. I've never seen him tell people how they "should" do it. Other respected DIY builders love the type 46. These people are not "industry experts". they are DIYers that love music. If I'm listening to lots and lots of records, stay up late want to listen to music first thing in the morning.... something is right. That what the 46 has been doing for me.

The weird thing is I have 3 pairs of speakers. ( as I'm writing this listing the the Belle) ...Altec Valencia, Klipsch Belle, and lii audio crystal 10s. The Altec at only 97dbs are the most unlikely pairing and they were so beautiful sounding. I'm sure they'd be great with the 45 to? I'm just into the 46. I have been listening to a lot of Rock and Roll, and a lot of Hard bop, and I listen mostly in the evening at lower levels. And my bass is supplemented with a sub woofer swarm.

Sorry. I don't have some heady wordy description of why I like it better.

 

[cal3713]

I'm not sure really I have been using a 45 for years. The past 3 months the 46. I tend to follow my heart. I read Thomas Mayers love for them. That's an influence. I respect him. I trust him. I use his gear. My experience with him, as a customer has been the best. He's very responsive. His build time was better than anyone I have every dealt with. His online presence is comendable. I've never seen him tell people how they "should" do it. Other respected DIY builders love the type 46. These people are not "industry experts". they are DIYers that love music. If I'm listening to lots and lots of records, stay up late want to listen to music first thing in the morning.... something is right. That what the 46 has been doing for me.

The weird thing is I have 3 pairs of speakers. ( as I'm writing this listing the the Belle) ...Altec Valencia, Klipsch Belle, and lii audio crystal 10s. The Altec at only 97dbs are the most unlikely pairing and they were so beautiful sounding. I'm sure they'd be great with the 45 to? I'm just into the 46. I have been listening to a lot of Rock and Roll, and a lot of Hard bop, and I listen mostly in the evening at lower levels. And my bass is supplemented with a sub woofer swarm.

Sorry. I don't have some heady wordy description of why I like it better.

A perfect description. I'm sold.

 

[Walnut Horns]

Don't forget the Type 50s. I'm currently listening to Cunningham 50s through my 107db horns and it sounds marvelous.

 

[Al M.]

Hello!
Would just like to add my two cents on the topic.
Having manufactured already many SET designs, like phono preamplifiers, line preamplifiers, MC step up transformers and of course power amplifiers, all with custom manufactured iron in double c core fashion, with custom ferromagnetic alloys, custom shapes and sizes, hand-wound everything with my own hands (and not simply to my own standards, wound by a third party), I can declare that I am in the position to give a very thoughtful reply, carrying on my back more than 15 years of transformers designing, winding, manufacturing and of course testing.
Pay attention: I am not referring to commercially available units but only to creations that escape from the classic barriers that have to do with spatial and financial obstacles and constraints. The reason is the excessively high cost. All pure SET designs make use of large number of iron pieces. Several of my creations make use of enormously large number of iron pieces, while my recommendations for highest level audio machines require ridiculous, insane amounts of iron. Good SET and cheap are two contradictory aspects.
I am referring to the topology done right.

Every single area! No exceptions!

Everything! No exceptions!

Absolutely not!

Entry level SET/horn combos would cost aprox. $50k, only for the amplifiers and speakers.
High quality SET/horn speaker combos definitely surpass the $100k mark.
For highest level of musical reproduction, $200-300k can very easily be reached and surpassed.

In high level designs there exists no coloration at all. In the designs that we are all experiencing at the various Hi-Fi shows around the globe, yes, coloration is a real issue, some times close to unbearable amounts of distortion. This does not mean that the concept / topology is to blame.

Hope all this helps...

Thank you, I appreciate your enthusiasm!

 

[cal3713]

Don't forget the Type 50s. I'm currently listening to Cunningham 50s through my 107db horns and it sounds marvelous.

Oh man, another typology to learn about!

 

[acg]

All pure SET designs make use of large number of iron pieces.

I'm building a phonostage with at last count 21 pieces of iron... pentode first stage and triode second stage... going to be heavy.

 

[bonzo75]

Peter's use of iron is quite extreme. His experiments on using every possible tube variation of 211 including WE 242c, and then using the various incarnations of telefunken 242/241 etc, is well documented on DIY audio.

Would love to hear his Altec based heavy iron amps with rare tubes once but I guess they are the most extreme at least that I have read about