Amp design

[JohnMichael]

This month's Stereophile magazine and particularly Sam's Space where he discusses the LFD integrated amp is interesting. Dr. Richard Bews is the founder, designer and builder of the amp. He has worked with the same overall circuit design for years to produce the same power level of 65 watts. What has changed from model to model is the sound based on the sound and quality of individual parts he can find.

My thoughts are this man must have incredible hearing to be able to choose from different parts. One of his comments was that individual parts are not as well made or sound as good today as parts manufactured years ago. Maybe the vintage folks are onto something. Shindo is another manufacturer that builds based on the sound of parts and uses some NOS parts he has collected.

I know of other designers that find circuit layout very important. The shortest path and all. We also have hugely powerful amps that use a large number of parts to produce that power.

Does anyone find it interesting how amps are designed and the huge number of choices available? Tube amps being hardwired instead of PC boards. I think in some ways at the design level amps are the most interesting to me.

I know we have some Nelson Pass fans here but does anyone else have a favorite amp or designer?

[Hyfi]

I don't know enough about amp design to have a favorite designer. But to address your comments, I have been researching to create a short list for when I downsize in a couple years. I was looking at the Leben CS600 Tube Integrated. The owner and designer of Leben products is Mr. Taku Hyodo who is ranked as one of the best eight tube audio design engineers in Japan.

I can't find the interview at the moment, but he said something like "An amp built with all high quality components that are just selected because of price/quality will not necessarily create a great sounding amp. One built where each component is listened to and then tested together is what creates a great sounding amp."

It's all about the synergy of all the components together, not on an individual basis.

[JohnMichael]

I think Dr. Bews must feel the same way. He was not name dropping expensive parts. He buys parts from all over the world based on sound.

He made an interesting statement that a properly optimized tube amp and a properly optimized transistor would sound the same.

[JoeE SP9]

A properly optimized amplifier, tube or SS should have the characteristics of a straight wire with gain.

If you believe that different wire materials sound different then the question becomes what kind of wire. Is it OF Copper, pure Silver, Silver plated Copper or something exotic?

S'cuse me. I'm trying to be difficult.

[JohnMichael]

A properly optimized amplifier, tube or SS should have the characteristics of a straight wire with gain.

If you believe that different wire materials sound different then the question becomes what kind of wire. Is it OF Copper, pure Silver, Silver plated Copper or something exotic?

S'cuse me. I'm trying to be difficult.


He was speaking of individual resistors, capacitors, etc. In the article he gave the reason for the new amp to better capacitors he found. He said bass was better and less grain. He never mentioned wire so you must have pulled that out of your....

[Hyfi]

A properly optimized amplifier, tube or SS should have the characteristics of a straight wire with gain.



Now cut that out, Joe. You're gonna have all those "All Amps should sound the same or they are defective" guys showing up. :)-

My Odyssey Stratos is wired with the same Groneberg IC cables I have that have a bassy characteristic.

http://images.audioasylum.com/usr/y2012/03/58652/Odyssey_Plus2B.jpg

[JohnMichael]

9731
Now cut that out, Joe. You're gonna have all those "All Amps should sound the same or they are defective" guys showing up. :)-

My Odyssey Stratos is wired with the same Groneberg IC cables I have that have a bassy characteristic.

http://images.audioasylum.com/usr/y2012/03/58652/Odyssey_Plus2B.jpg


That looks like a well designed amp. Power amps look a little cleaner than integrated amps. My Krell S-300i has the preamp back by the RCA's and balanced inputs. Center transformer and dual power amps for L and R channels.

[bfalls]

All components have values with tolerances, normally 10% or 5% for caps and inductors and 10%, 5% and 1% for resistors (wire-wound). I could see where different components of different tolerances could make differences either additive or subtractive in sound due to their reactance at different frequencies. Values can also change with temperature.

[Hyfi]

JM, take a look at this thread if you can. One of the members on that forum, and in the pictures builds some nice stuff.

Black Beauties! (http://audioshark.org/amplifiers-8/black-beauties-5106.html#.U6DQ-ChmqtU)

http://audiofederation.com/ces-2012/m/IMG_3665-tenor-audio-175S-amplifier-open-chassis-small.jpg

http://i1180.photobucket.com/albums/x415/parlee2/10257097_647261298688063_3364074970689627606_o_zps 3a4585b0.jpg

[Mr Peabody]

It's interesting he feels older parts sound better, you'd think with better technology would come better parts. For instance, those Toshiba output devices which is the equivalent of two transistors in one case. We definitely have better power supplies now opposed to then. I'd be some hesitant to buy a high dollar amp using a lot of NOS parts unless I was assured the company had a large enough stock to guarantee service in the future.

Hyfi, if you have the budget for Leben I'd urge you to listen to Octave Audio before deciding. They use tubes but have the control and transparency of good solid state, it just sounds right.

There's several good amp designers out there, D'Agustino comes to mind, Krell's history has some great amps. The team of Conrad & Johnson for their ability to some how make their amps breathe soul into the music. Of course, I'm a Pass fan.

[Hyfi]

It's interesting he feels older parts sound better, you'd think with better technology would come better parts.

Hyfi, if you have the budget for Leben I'd urge you to listen to Octave Audio before deciding. They use tubes but have the control and transparency of good solid state, it just sounds right.



Mr P, I agree to some point, but why are we all seeking out NOS Tubes? Because today's EHs and Sovteks and JJs just are not the same as a '50s-'60 era RCA Clear Top or Long Plate.

I also wonder what it is all those guys at AK are hearing with their 70s era Sansuies and Lamp Cord to think they all sound better than today's gear.

Thanks for the tip on Octave, very nice looking gear. Looks like they are a bit more than the Leben by a few thousand.

I am just coming up with possibilities and a short list for a downsized killer setup for a smaller house and room. I am liking the Rogue Magnum Kronus for the price and reviews. I have yet to hear Pass gear and can never seem to get the timing right to visit Jack, but hope to.

[Feanor]

JM, take a look at this thread if you can. One of the members on that forum, and in the pictures builds some nice stuff.

Black Beauties! (http://audioshark.org/amplifiers-8/black-beauties-5106.html#.U6DQ-ChmqtU)

That's the Tenor 175S stereo amp, (HERE (http://www.tenoraudio.com/collection_175S.html)). Pretty spectacular looking. It's a tube/solid state hybrid; I'm not exactly sure why you need 6 tubes per channel in a hybrid but there it is. It's obviously a "no compromise" design.

http://www.soundclub.pl/files/products/158/TenorAudio_175S_internal.jpg

[Hyfi]

Yep, friggin awesome looking and sound from what I have read. Only $55K suggested price :)

[Feanor]

It's interesting he feels older parts sound better, you'd think with better technology would come better parts. For instance, those Toshiba output devices which is the equivalent of two transistors in one case. We definitely have better power supplies now opposed to then. I'd be some hesitant to buy a high dollar amp using a lot of NOS parts unless I was assured the company had a large enough stock to guarantee service in the future.
...

There's several good amp designers out there, D'Agustino comes to mind, Krell's history has some great amps. The team of Conrad & Johnson for their ability to some how make their amps breathe soul into the music. Of course, I'm a Pass fan.
I think it's mainly vacuum tubes where the older might sound better -- at least to some ears. When I had my Sonic Frontiers Line 1, it was a pair of Amperex PQ 6922's that sounded best: these tube were probably made in the early '60s. I bought mine used for about $85 the pair; true "NOS", (new old stock), run upwards $250 each.

I love my Pass X150.5. John Atkinson of Stereophile and my personal favorite review likes Pass Labs too. Not long ago he said the pair of XA60.5's he reviewed were the best sounding amps he ever heard. He like best about them what I like best about my X150.5: the ability to carve palpable, haut relief images in the soundstage.

But I don't consider my X150.5 to be quite perfect, i.e. in combination with my other equipment. On the up-side, in addition to the amazing imaging, I find it has great dynamic contrast, (PRaT), and to deliver a bass which is about the perfect combination of precision and weight. On the down-side, especially with less than great recordings and at higher volumes, there is a sort of discontinuity of the top highs which can become a slightly harsh and aggressive, (though much less so than my Class D Audio SDS-258); also, it seems to project solo instruments and voices a bit further forward in the soundstage than is ought to be the case. This are relatively minor criticisms overall.

[JoeE SP9]

He was speaking of individual resistors, capacitors, etc. In the article he gave the reason for the new amp to better capacitors he found. He said bass was better and less grain. He never mentioned wire so you must have pulled that out of your....

I was trying to inject a little humor. I'm a believer in the different sound of passive and active electronic components.

Hifi: AFAIK there is no such thing as properly (perfectly) optimized amplifier. That's why they all sound slightly different. Anyway, during a visit to my ENT/Cancer doctor yesterday, he cleaned my ears. So right now I'm a lean mean listening machine!

[Mr Peabody]

When I heard Leben I believe the model was around $4k integrated but they may have more entry models. Octave has a 40 watt integrated around $4k, although it's one of the strongest 40 watts I've ever heard, especially with the upgraded power supply for extra $$$.

Pass has a couple nice integrated amps either 150x2 which is similar to the 150.5 in the power section or 30x2 pure Class A.

I can understand older tubes sounding better, most manufacturers closed and today it's almost like finding the plans and trying to recreate them.


Mr P, I agree to some point, but why are we all seeking out NOS Tubes? Because today's EHs and Sovteks and JJs just are not the same as a '50s-'60 era RCA Clear Top or Long Plate.

I also wonder what it is all those guys at AK are hearing with their 70s era Sansuies and Lamp Cord to think they all sound better than today's gear.

Thanks for the tip on Octave, very nice looking gear. Looks like they are a bit more than the Leben by a few thousand.

I am just coming up with possibilities and a short list for a downsized killer setup for a smaller house and room. I am liking the Rogue Magnum Kronus for the price and reviews. I have yet to hear Pass gear and can never seem to get the timing right to visit Jack, but hope to.

[Hyfi]

Not the best pic, but here are the guts of my Counterpoint NPS-400 Hybrid Amp ( the main tubes were being swapped so they are not in the sockets near the top of pic)

http://i1249.photobucket.com/albums/hh507/Hyfi61/IMG_4100_zpsce2a6a39.jpg

[Glen B]

Not the best pic, but here are the guts of my Counterpoint NPS-400 Hybrid Amp

Here you go. Flaws can be easily fixed with an image editor. There are a few decent basic ones available that are free.

9732

[frenchmon]

JM, take a look at this thread if you can. One of the members on that forum, and in the pictures builds some nice stuff.

Black Beauties! (http://audioshark.org/amplifiers-8/black-beauties-5106.html#.U6DQ-ChmqtU)

http://audiofederation.com/ces-2012/m/IMG_3665-tenor-audio-175S-amplifier-open-chassis-small.jpg

http://i1180.photobucket.com/albums/x415/parlee2/10257097_647261298688063_3364074970689627606_o_zps 3a4585b0.jpg

Hyfi...thats my dream amp....if I had upwards of $75,000,00 I would buy that Tenor amp...and yes they build nothing but Hybrids.

[frenchmon]

Yep, friggin awesome looking and sound from what I have read. Only $55K suggested price :)

You want to see the Tenor in action click on the second video and at the end of the review of the gear he fires them babies up!

WGAS (http://www.avshowrooms.com/WGAS.html)

[Hyfi]

Hyfi...thats my dream amp....if I had upwards of $75,000,00 I would buy that Tenor amp...and yes they build nothing but Hybrids.

Yeah, they are drop dead gorgeous, but only $55K :)

[frenchmon]

When I heard Leben I believe the model was around $4k integrated but they may have more entry models. Octave has a 40 watt integrated around $4k, although it's one of the strongest 40 watts I've ever heard, especially with the upgraded power supply for extra $$$.

Pass has a couple nice integrated amps either 150x2 which is similar to the 150.5 in the power section or 30x2 pure Class A.

I can understand older tubes sounding better, most manufacturers closed and today it's almost like finding the plans and trying to recreate them.

I understand Leben has a more SS sound to them being tubes...also Shindo and many of the others like Line Magnetic are based on the old Western Electric designs and my actually use some of those old parts which they say sound much better than todays parts....its all in the ear of the hearer if you ask me.