How Bad is Owning Class A?

[Santy]

It looks like Class A vs AB is somewhat similar to the 2-stroke vs 4-stroke IC engine comparison.

 

[Kushanava]

I wonder how this thread narrowed down to the sugden since I never mentioned..

I am actually narrowing down to a sugden A21se. Class A is one of the biggest hurdles on the way

Hello, I am owning this exact amp.I am driving the dyns x12 with it.
Well i did an A to B comparison with the amps like , Mf m3i , exposure 2010s ,
Sugden a21a . To my ears , nothing came close to an a21 se .
They drove the dyns with authority at low volumes , which none of the other amps could.Yes , high sensitivity speakers is what you need if you want to play them at a high volumes , and I mean really high volumes where you need to fill up a room > 400Sqft , but at the same time , this amp is never a slow poke with the heavy loads.It drove the 83 DB Spendors in a small room (listening distance 6 /7 ft) with fast transients.This is were it is very diff from the a21a .It has much tighter bass and more control than the a21a.Also the heat generated is lesser than the a21a.

What speakers do you have ? I always wanted to listen to a PROAC and a HARBETH with this amp .

 

[BLASTO]

Hello, I am owning this exact amp.I am driving the dyns x12 with it.
Well i did an A to B comparison with the amps like , Mf m3i , exposure 2010s ,
Sugden a21a . To my ears , nothing came close to an a21 se .
They drove the dyns with authority at low volumes , which none of the other amps could.Yes , high sensitivity speakers is what you need if you want to play them at a high volumes , and I mean really high volumes where you need to fill up a room > 400Sqft , but at the same time , this amp is never a slow poke with the heavy loads.It drove the 83 DB Spendors in a small room (listening distance 6 /7 ft) with fast transients.This is were it is very diff from the a21a .It has much tighter bass and more control than the a21a.Also the heat generated is lesser than the a21a.

What speakers do you have ? I always wanted to listen to a PROAC and a HARBETH with this amp .

My speakers are Thiel CS1.6.
92db sensitivity and 4ohm stable load.

A sugden mystro drives it well.. Looks like it is the most powerful amp of sugden with 50w/ch A/B.

Where have you placed the amp? Does it need A/C all the time? Can it reside in a TV cabinet or require a hifi rack?

 

[arj]

Hello, I am owning this exact amp.I am driving the dyns x12 with it.
Well i did an A to B comparison with the amps like , Mf m3i , exposure 2010s ,
Sugden a21a . To my ears , nothing came close to an a21 se .
They drove the dyns with authority at low volumes , which none of the other amps could.Yes , high sensitivity speakers is what you need if you want to play them at a high volumes , and I mean really high volumes where you need to fill up a room > 400Sqft , but at the same time , this amp is never a slow poke with the heavy loads.It drove the 83 DB Spendors in a small room (listening distance 6 /7 ft) with fast transients.This is were it is very diff from the a21a .It has much tighter bass and more control than the a21a.Also the heat generated is lesser than the a21a.

What speakers do you have ? I always wanted to listen to a PROAC and a HARBETH with this amp .

the 21se is different from, 21a it has a higher power output at 4 ohms and thats why its diriving the Dyns well..else it could do so only at low volumes.

the Proacs, spendor are both supposed to be great with this. The Harbeths (non monitor) might sound a bit sluggish from reports i have heard.

Spendors depite their lower sensitivity are very easy loads

 

[Kushanava]

My speakers are Thiel CS1.6.
92db sensitivity and 4ohm stable load.

A sugden mystro drives it well.. Looks like it is the most powerful amp of sugden with 50w/ch A/B.

Where have you placed the amp? Does it need A/C all the time? Can it reside in a TV cabinet or require a hifi rack?

It is on the top tier of my shelf.i dont use AC that much.
I have never heard a thiel , so can't comment on the pairing ..

I may in future upgrade to a rethm and try a match ..It would be interesting ..

 

[arj]

More on Class A
there is a Pure Single Ended Class A. this is basically a transister version of the SET and is also aclled Pure Class A. there is not signal split and is 100% calss A for the entire power range
The Sugden A21 falls into this category..and I believe so do the accuphase

then there is a biased Class A. it si a Class AB amp with a very high bias (30-80%) hence while the signal is still getting split like a push pull, it draws the entire Bias current as long as it is in Class A and only in case the load needs more power does it switch to class AB for the incremental power (and hence more draw form the mains)
http://www.firstwatt.com/pdf/art_leave_classa.pdf

pass labs/Plinius falls into this

It is on the top tier of my shelf.i dont use AC that much.
I have never heard a thiel , so can't comment on the pairing ..

I may in future upgrade to a rethm and try a match ..It would be interesting ..

I am really not sure if the Rethm is a good match with this..they will sing with SETs and tubes. and i believe need far less power and can handle much higher resolution than what the sugden is rated for.

but the Rethms are some speakers...has been the only lowther based speaker (from what I have heard) that i have liked !

 

[arj]

My speakers are Thiel CS1.6.
92db sensitivity and 4ohm stable load.

A sugden mystro drives it well.. Looks like it is the most powerful amp of sugden with 50w/ch A/B.

Where have you placed the amp? Does it need A/C all the time? Can it reside in a TV cabinet or require a hifi rack?

Blasto, I have only heard of thiels being run with higher powered amps..i dont know enough about it but sensitivity/impedance is not the only factor to look at
you need to see the min impedance and the phase on the frequency response.

If you are buying blind, the you take a lower risk with Higher power amps. Unless you do find someone who runs it with a similar setup

 

[arj]

Here goes

However, the '1.6 does suck more than twice as much current as an 8 ohm speaker from the amplifier to achieve that high sensitivity, as revealed by its plot of impedance magnitude and electrical phase against frequency (fig.1). The phase angle is generally lowa good thing, in that it doesn't amplify the speaker's current demandsbut the combination of 5.1 ohms magnitude and 48 degrees capacitive phase at 129Hz might stress an optimistically specified receiver or amplifier.

the sugden is great for 8ohms and upto 4 ohms on easy to drive speakers...thiel is not really classified as an easy to drive despite what its sensitivity shows.