[squirt]

Hello, i was considering upgrading my original version Max amp with a current headroom amp such as the Ultra Desktop and was wondering how these two amps compare sonically? any comments would be appreciated.

regards

 

[TheSloth]

Quote:

Originally Posted by squirt /img/forum/go_quote.gif Hello, i was considering upgrading my original version Max amp with a current headroom amp such as the Ultra Desktop and was wondering how these two amps compare sonically? any comments would be appreciated. regards

Original version as in 2000?

 

[squirt]

i can't remember when i got the max but i was thinking it was before 2000. it's the very first max version HR came out with. it uses the 627 opa like the ultra but was wondering if HR has been able to improve the sonic quality of their amps since the max. i've been almost entirely out of the high end audio loop for many years now so i have no idea where things stand today. i didn't even know HR doesn't make a max anymore till today.

 

[TheSloth]

Quote:

Originally Posted by squirt /img/forum/go_quote.gif i can't remember when i got the max but i was thinking it was before 2000. it's the very first max version HR came out with. it uses the 627 opa like the ultra but was wondering if HR has been able to improve the sonic quality of their amps since the max. i've been almost entirely out of the high end audio loop for many years now so i have no idea where things stand today. i didn't even know HR doesn't make a max anymore till today.

Yay, my pet subject!

Yes, significantly so. Your amp uses the 627 for gain and summer stages, and the OPA275 to handle the crossfeed. There is no extra bias applied to these, so they remain class A/B.

The output stage was a very simple push pull transistor pair, also running in class A/B.

The current modules use the 627 for all signal stages, including crossfeed, and have significant class A bias applied through FET constant current sources. The output stage is the much more sophisticated Diamond Buffer, again with significant class A biasing applied. The output transistors are also of a higher quality. The crossfeed circuit itself has also been redesigned somewhat, and is markedly improved to my ears.

However, the rest of the amp is not hugely different. Your Max includes dual L and R power supplies with some pretty boutique power transformers, and a good volume pot (or stepped attenuator?), and so unless you were desperate for a built in DAC, there would be absolutely no reason to throw this away. Simply get the modules changed to the current Max Modules and you're good to go...

 

[Tyll Hertsens]

Quote:

Originally Posted by TheSloth /img/forum/go_quote.gif Yay, my pet subject!.... Simply get the modules changed to the current Max Modules and you're good to go...

Say, where you living these days, mang? I owe you dinner and need to know when I happen to be in your neighborhood.

 

[Dan Millheim]

How does the 2007 Home Max compare with the Ultra? Thanks.

 

[Tyll Hertsens]

It takes less space on your desk.

Sorry. They sound very much the same ... very much.

 

[Dan Millheim]

Quote:

Sorry. They sound very much the same ... very much.

Thanks Tyll

 

[squirt]

Quote:

Originally Posted by TheSloth /img/forum/go_quote.gif Yay, my pet subject! Yes, significantly so. Your amp uses the 627 for gain and summer stages, and the OPA275 to handle the crossfeed. There is no extra bias applied to these, so they remain class A/B. The output stage was a very simple push pull transistor pair, also running in class A/B. The current modules use the 627 for all signal stages, including crossfeed, and have significant class A bias applied through FET constant current sources. The output stage is the much more sophisticated Diamond Buffer, again with significant class A biasing applied. The output transistors are also of a higher quality. The crossfeed circuit itself has also been redesigned somewhat, and is markedly improved to my ears. However, the rest of the amp is not hugely different. Your Max includes dual L and R power supplies with some pretty boutique power transformers, and a good volume pot (or stepped attenuator?), and so unless you were desperate for a built in DAC, there would be absolutely no reason to throw this away. Simply get the modules changed to the current Max Modules and you're good to go...

TheSloth, thanks for all your help. that's some great info. i will be contacting HR to see about a module upgrade for my max.

regards and thanks again

 

[squirt]

unfortunately it turns out my max amp is of a too old vintage to upgrade with the max module so i'll have to look at other options.

would it be possible to get an desktop ultra without the DAC as an option? the micro ultra looks like another nice amp to consider.

 

[squirt]

double post