Sanders Sound Systems - electrostatic

[Angela]

Dagogo just published an interview with Roger.

Here's the link if anyone cares to read it http://www.dagogo.com/View-Article.asp?hArticle=991

Cheers,
Angela

 

[hvbias]

Hello everyone

I am new to WBF, but have been lurking and reading many of the threads here. There is some terrific information in this forum and I'd like to thank Angela for relaying the posts from Roger. Post # 54 was especially extremely useful to me, an electrostat lover.

If you're still checking in on this thread I'd love to hear Roger's thoughts on solid state amps operating in pure class A vs highly biased class A that drop out of class A at higher power levels, vs class A/B amps for electrostatic speakers.

Cheers

-Deepak

 

[DonH50]

Highly biased class A that drops out at higher power is class AB...

I am pretty sure Roger's are AB but am also sure he or Angela will step in.

I have driven 'stats with Class A monoblocks (Krell, ML, Threshold, couple of others I have forgotten) and AB amps. Honestly not sure I heard much difference within their power bands. More difference among amp designs and power levels than operating class... However, a 50 W pure class A fared much better than a 50 W class AB, true.

I would not try driving them with a SET... I have tried tube amps (not the huge ARC 600, though) and by and large do not feel they do as well in the bass or very highs; gorgeous midrange, however.

 

[hvbias]

Highly biased class A that drops out at higher power is class AB...

I understand. I should have been more clear and said highly biased class A/B vs lower biased class A/B where class A drops out after a couple of watts (the higher biased Class A/B amps being something like Pass that drop out of class A at 50+ watts).

I am curious because I have heard Nelson Pass's take on the issue, but would love to hear others.

 

[Angela]

Hello everyone

I am new to WBF, but have been lurking and reading many of the threads here. There is some terrific information in this forum and I'd like to thank Angela for relaying the posts from Roger. Post # 54 was especially extremely useful to me, an electrostat lover.

If you're still checking in on this thread I'd love to hear Roger's thoughts on solid state amps operating in pure class A vs highly biased class A that drop out of class A at higher power levels, vs class A/B amps for electrostatic speakers.

Cheers

-Deepak

Hello, Deepak.

Thanks for the post. I'll send your question along to Roger and post when he responds.

Happy Friday, everyone!

It is SOOOOO HOT here. We are not used to it getting so hot up here at 9,000'

Cheers,
Angela

 

[puroagave]

I understand. I should have been more clear and said highly biased class A vs Class A/B where class A drops out after a couple of watts (the higher biased Class A amps being something like Pass that drop out of class A at 50+ watts).

I am curious because I have heard Nelson Pass's take on the issue, but would love to hear others.

your follow up is more confusing. I think you mean high bias class A/B that runs pure class A for so many watts and then A/B thereafter. with 50-watts of pure class A power you can still get 100 db of SPL before it shifts to A/B, this with a speaker of 86db sensitivity w/ one watt input. above 100 db SPL the distortion artifacts of said speaker would swamp any distortion from even the 'dirtiest' A/B amp you can find. distortion in speakers is an order of magnitude higher than the electronics driving them.

 

[hvbias]

your follow up is more confusing. I think you mean high bias class A/B that runs pure class A for so many watts and then A/B thereafter. with 50-watts of pure class A power you can still get 100 db of SPL before it shifts to A/B, this with a speaker of 84db sensitivity w/ one watt input (pretty low sensitivity by todays standards). above 100 db SPL the distortion artifacts of said speaker would swamp any distortion from even the 'dirtiest' A/B amp you can find. distortion in speakers is an order of magnitude higher than the electronics driving them.

I've gone back and edited my post to make it more clear. But you're correct in what I meant.

What is the benefit of a pure class A 200 watt amp vs a Class A/B amp that drops out of class A at 60 watts, but is rated for 1000 watts (we'll say for electrostatic speakers given the thread is about Sanders Speakers)?

It was Roger's reply in post 54 that sparked my curiosity since his ESL amps are good for a thousand watts.

 

[puroagave]

pure class A's selling points were low to non existent notch distortion, imo the jury is still out as to whether this is audible vs-a-vis a high quality A/B amp. The reason others like me used them was the stability into any load to almost a dead short, and the succesive double of power with each halving of the impedence. Ive owned Soundlab electrostics that posed a 1-ohm load at high frequencies, the amps i used were krell ksa-250 and mda-500s but Rowland 7s (class A/B) worked just as well. i have direct experience with all non-reference series krells up to the early '90s, since then Krell have become high bias A/B but still deliver high current.

to stir the pot some more, the biggest proponent of class-A, the guy who spent 30-yrs building his reputation on it, now only builds A/B amps (low bias at that) and says it his best work ever (D'Agostino)

 

[MylesBAstor]

pure class A's selling points were low to non existent notch distortion, imo the jury is still out as to whether this is audible vs-a-vis a high quality A/B amp. The reason others like me used them was the stability into any load to almost a dead short, and the succesive double of power with each halving of the impedence. Ive owned Soundlab electrostics that posed a 1-ohm load at high frequencies, the amps i used were krell ksa-250 and mda-500s but Rowland 7s (class A/B) worked just as well. i have direct experience with all non-reference series krells up to the early '90s, since then Krell have become high bias A/B but still deliver high current.

to stir the pot some more, the biggest proponent of class-A, the guy who spent 30-yrs building his reputation on it, now only builds A/B amps (low bias at that) and says it his best work ever (D'Agostino)

Dan's son however builds Class A amps. I think one reason Dan changed course in midsttream, besides the heat issue, is that it's very hard to design large wattage Class A amps

 

[puroagave]

Dan's son however builds Class A amps. I think one reason Dan changed course in midsttream, besides the heat issue, is that it's very hard to design large wattage Class A amps

i think the latest EU green requirements for consumer electronics is stiff. something like the mda-500 probably couldnt be exported today. quiescent current was awesome, i could trip a 20-amp breaker if i switched them on within a second or two. theres a whole generation of audiophiles that will never know the amplfier equivalent of a 3-mpg race car

 

[hvbias]

pure class A's selling points were low to non existent notch distortion, imo the jury is still out as to whether this is audible vs-a-vis a high quality A/B amp. The reason others like me used them was the stability into any load to almost a dead short, and the succesive double of power with each halving of the impedence. Ive owned Soundlab electrostics that posed a 1-ohm load at high frequencies, the amps i used were krell ksa-250 and mda-500s but Rowland 7s (class A/B) worked just as well. i have direct experience with all non-reference series krells up to the early '90s, since then Krell have become high bias A/B but still deliver high current.

to stir the pot some more, the biggest proponent of class-A, the guy who spent 30-yrs building his reputation on it, now only builds A/B amps (low bias at that) and says it his best work ever (D'Agostino)

I'm sure Dan's new amps sound great. But how much of it was built for sound quality and how much of it for a person looking for a compact, attractive amp that will slide into a small space in their living room rack...

I can't be the only one wondering why he would go from decades of building class A and sliding bias class A amps to this super compact A/B amp.

I'm not anti- A/B. One of my favorite amps is the Ayre MX-R.

 

[Gregadd]

I'm sure Dan's new amps sound great. But how much of it was built for sound quality and how much of it for a person looking for a compact, attractive amp that will slide into a small space in their living room rack...

I can't be the only one wondering why he would go from decades of building class A and sliding bias class A amps to this super compact A/B amp.

I'm not anti- A/B. One of my favorite amps is the Ayre MX-R.

One answer might be lawsuit. When you are in litigation with the new owners of your old company you try to avoid making similar products.

 

[MrAcoustat]

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[puroagave]

i had a DR-2, it was a honey of an amp, wish i still had one to drive my quad 57s.

 

[DonH50]

This is drifting pretty far from Sander's Electrostatic Speakers...

 

[puroagave]

when the honoree doesnt show up to his own party (Roger) the atendees end up talking among themselvers

Staying on topic, i did hear SSS at the recent Newport show and they're great. maybe roger can elaborate on why he prefers flat panels over curved ones a la ML, soundlab, et al.

 

[MrAcoustat]

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[FrantzM]

Yes you're right, but for ME electrostatics are FULL RANGE ,no boxes.

Hi

Have you heard the Sanders ESL?

 

[MrAcoustat]

Post deleted

 

[FrantzM]

Mr Acoustat

My question didn't imply that you thought they didn't sound good. Only that direct and careful audition would allow one to form a definitive and objective assessment... That's all...