Amp to drive hf horns and tweeters?

[retro soulman]

Hello! Happy holidays to all of you, with health and hapiness
Well im very happy with the sound of my JBL system, but i want to make a big change on the amp that drives my hf horns and tweeters. My system is biamped with a 2 way bss crossover and i use a passive one just for the tweeters , the speakers are the jbl 4530 loaded with jbl k140, on mid horns i got the 2445 on 2390 lenses and a 2402 tweeter. The amp for the lows is a crown psa2 and for the mid & highs a Sound Valves vta70. The sound of the system is very warm and detailed with nice soundstage . Im very pleased but i want to remove the tube amp from the system. I just want to be full solid state. Even if i found a amp with the same sound with the sound valves but in solid state ill be happy! So, any suggestions for an amp with that warm but detailed sound that will not change the character of my speakers much? Class a? Mosfet? Any brands? I see that in japan accuphase is popular with horns but i think they are a little bright for horns, same with bryston. Small krell? ML? I would also like to be close to the rest age of my system. Best regards!!

[Mr. Widget]

Hello! Happy holidays to all of you, with health and hapiness
Well im very happy with the sound of my JBL system, but i want to make a big change on the amp that drives my hf horns and tweeters. My system is biamped with a 2 way bss crossover and i use a passive one just for the tweeters , the speakers are the jbl 4530 loaded with jbl k140, on mid horns i got the 2445 on 2390 lenses and a 2402 tweeter. The amp for the lows is a crown psa2 and for the mid & highs a Sound Valves vta70. The sound of the system is very warm and detailed with nice soundstage . Im very pleased but i want to remove the tube amp from the system. I just want to be full solid state. Even if i found a amp with the same sound with the sound valves but in solid state ill be happy! So, any suggestions for an amp with that warm but detailed sound that will not change the character of my speakers much? Class a? Mosfet? Any brands? I see that in japan accuphase is popular with horns but i think they are a little bright for horns, same with bryston. Small krell? ML? I would also like to be close to the rest age of my system. Best regards!!

I would go with a small Class A amp, vintage or new. The Bedini 25watt stereo amp is excellent and affordable if you can find one. There are numerous others as well.


Widget

[Mitchco]

Happy New Year!
If you are handy with a soldering iron, Nelson Pass Class A single ended mosfet design kit has a wonderful tube like sound and works well with compression drivers.

I use these on JBL 4722's 2453h-SL CD and sound smooth, but detailed. They are a good match for compression drivers due to their low voltage gain, so you don't need to pad them down, just a protection cap for turn off thump. The stock Meanwell power supply is low noise - I have to put my ear near the mouth of the waveguide to hear a faint hiss.

Good luck with whatever you choose!

[retro soulman]

Yeap 60 watts are more than enough for me ! What i want is good sound and safe operation. My 35wpc of my tube watts are enough but i wouldnt say no ti 60wpc !

[Dr.db]

Thanks

[HCSGuy]

Happy New Year!
If you are handy with a soldering iron, Nelson Pass Class A single ended mosfet design kit has a wonderful tube like sound and works well with compression drivers.

I use these on JBL 4722's 2453h-SL CD and sound smooth, but detailed. They are a good match for compression drivers due to their low voltage gain, so you don't need to pad them down, just a protection cap for turn off thump. The stock Meanwell power supply is low noise - I have to put my ear near the mouth of the waveguide to hear a faint hiss.

Good luck with whatever you choose!

Thanks for the motivation! I have a pair of the Amp Camp kits that have been sitting around for some months, unbuilt - I'm remodeling my music room, but am hopeful that I'll have time to fit in an amp build between finishing the remodel and Spring chores starting - glad to hear you like them

[Dr.db]

When using an amp directly coupled to a high sensitivity horndriver, what spec is most important to look at?
Is it the Signal-to-Noise ratio?
Which value is sufficient to keep it quiet? 90db a-weighted?

I would go with a small Class A amp, vintage or new. There are numerous others as well.


Widget

Could you list the ones that are available new please?


@ Pos & Bubbleboy:

Does the THX AAA 789 really handle an 8ohm load of a compressiondriver? It looks like it is only specifid for 16ohms minimum...
Have you driven these with serious spl levels yet? Or are these only suitable for moderate listening levels?

[Mr. Widget]

Could you list the ones that are available new please?

The Pass Labs XA25 is likely one of the best amps ever made for this application.

https://www.passlabs.com/amplifier/xa25

https://www.stereophile.com/content/...ower-amplifier

https://6moons.com/audioreviews2/passlabs3/1.html


Widget

[pos]

@ Pos & Bubbleboy:

Does the THX AAA 789 really handle an 8ohm load of a compressiondriver? It looks like it is only specifid for 16ohms minimum...
Have you driven these with serious spl levels yet? Or are these only suitable for moderate listening levels?

8 ohm nominal (so around 6 ohm min for a typical JBL compression driver) is definitely too low for that amp.
A LPUHP amp would be a better match.

The THX is the perfect match for a 16 or 32 ohm compression driver, and will let you reach 105dB SPL/1m no problem after constant directivity equalization (on sinusoidal signals, and much more on real-world signals given the typical spectral power distribution of music).

[Dr.db]

8 ohm nominal (so around 6 ohm min for a typical JBL compression driver) is definitely too low for that amp.

The JBL 2441 is rated 16ohms, but I think in reality it´s rather 8ohm or am I wrong? Would this work with this THX headamp?

[pos]

16 ohm JBL compression drivers have a minimum impedance of around 12 ohm in the passband (Re might be lower, but is irrelevant here).

Bubbleboy is running his 16 ohm 476Mg with the THX. I think he uses the SE output.

[RMC]

Hi Retro Soulman,

Best wishes for the new year to yourself also.

I'm a small size amp lover for a number of reasons, one being for the flexibility they allow me to have.

There's not a whole lot of small Pro amps left in the new gear market, but here's a few suggestions to look at. I tend to prefer Pro ones over more "exotic" brands like Krell, Levinson, Pass, etc. for practical reasons.

Note that Bryston isn't mentioned here by me because Earl has already commented elsewhere about a couple of issues with these, also with the use of HF drivers...

MOSFET? Sure why not. The only one I know of that still exists new, plus that I will possibly purchase in the new year, is the Rolls RA 200 studio amp. Don't know if available in Europe, you would need to check with them (rolls.com). They have other smaller ones but not MOSFET as I recall. I remember in the old days when these were more popular, MOSFET amps were said to overload more gracefully than conventional ones. In case you want to read two small paragraphs from someone who knows about MOSFET circuit design and its advantages, let me know I'll post them with reference (and its not even from Rolls).

Crest Audio PA 150 or IPS 150 are other options, though they might have been discontinued recently. However, there could still be some units available in the local distribution system. Another one to check.

Ashly SRA series models 2075 (2 channels) or 4075 (4 channels). I purchased recently two 2150 from that same series.

All the above are convection cooled, so no fan noise, and use one rack space, except for Rolls RA 200 at two rack spaces. Best regards,

Richard

[retro soulman]

Hi Retro Soulman,

Best wishes for the new year to yourself also.

I'm a small size amp lover for a number of reasons, one being for the flexibility they allow me to have.

There's not a whole lot of small Pro amps left in the new gear market, but here's a few suggestions to look at. I tend to prefer Pro ones over more "exotic" brands like Krell, Levinson, Pass, etc. for practical reasons.

Note that Bryston isn't mentioned here by me because Earl has already commented elsewhere about a couple of issues with these, also with the use of HF drivers...

MOSFET? Sure why not. The only one I know of that still exists new, plus that I will possibly purchase in the new year, is the Rolls RA 200 studio amp. Don't know if available in Europe, you would need to check with them (rolls.com). They have other smaller ones but not MOSFET as I recall. I remember in the old days when these were more popular, MOSFET amps were said to overload more gracefully than conventional ones. In case you want to read two small paragraphs from someone who knows about MOSFET circuit design and its advantages, let me know I'll post them with reference (and its not even from Rolls).

Crest Audio PA 150 or IPS 150 are other options, though they might have been discontinued recently. However, there could still be some units available in the local distribution system. Another one to check.

Ashly SRA series models 2075 (2 channels) or 4075 (4 channels). I purchased recently two 2150 from that same series.

All the above are convection cooled, so no fan noise, and use one rack space, except for Rolls RA 200 at two rack spaces. Best regards,

Richard

I dont know if the "pro" solution is a good idea to drive the horns because thats where is all the resolution and character of the speaker. I had try a small bgw 100b, good mids but not good highs, also a small bryston 2b, good sound but no character (and some hiss ). I believe a class a amp will be the closest thing in sound to my tube power amp!

[Ian Mackenzie]

I would have a look over on Diyaudio Store. If you can’t solder get a friend to help.

Aside from the Amp Camp design the Aleph 30 is a nice diy option. This is a very smooth and clean SE class A mosfet amp.

Nelson Pass has a number of impressive amps under his First Watt brand that would be excellent.

I suggest you send him an email. He always replies and is very helpful.

[pos]

I am using the THX AAA 789 on my D2430K, and it does wonders!