I posted this on the end of an earlier thread but suspect it didn't get noticed. Should be of interest to anyone thinking of building a Tripath EVM board into an amp. Any comments welcome!!!
Like the others above I have been interested to follow recent developments in switching amps. Tripath and amplifiers using Tripath technology have had great press - and the evm modules are reasonably priced so I decided to give one a go.
Its summer here in NZ and despite a cold summer, 1kW of class A from a Plinius SA250 in my lounge is a bit much, so I though maybe I could try a Class D amp and maybe oust the Plinius and save a few bucks on the way past. My set up is not bad, SACD, TT, good valve pre, SA250 and N801's - and is going rather nicely (at last!). So I'm in a very good position to compare results from the Tripath amp and the Plinius (which I find increasingly hard to fault).
Just to add interest my profession involves me with design of very high power class D amplifiers (to about 750kW) - better known as inverters. The techniques of these are completely similar to those used in making class D work well - at least from an electrical engineering perspective.
I had little difficulty in getting the EVM module going (forget the number but it’s the largest one - about 300+W into 8 ohms). For the sake of peace of mind I fitted the speaker protection components which Tripath leave off the big module (I'm not running it near full power).
The result is a very "nice" sound. Very smooth, nothing offensive makes cds and records that are unlistenable through the Plinius quite pleasant by taking the harshness away. Unfortunately this is definitely a filtering process and the life and energy (air, feeling of energisation in the room) in the music go out the back door too. The bad cds I refer to are bad - it isn't the Plinius mucking them up - it just plays them as they are.
Most of the smoothing effect is in the highs. The mids seem OK but I think maybe recessed. The upper bass is not especially tight (but this may be my power supply not being big enough - I'll borrow 47kuF and add that tomorrow and see what difference it makes). My 801's need very well controlled bass or the 15inch woofers take over the sound - they sound relatively boomy with the Tripath amp.
I've incorporated all tweaks I could find on the net - except input transformers (but I have wound the input coax cable around large common mode cores appropriate for rf suppression at the frequencies used in the amp module).
I'm open to any suggestions as to how to get better sound out of the amp. Please let me know your thoughts!
My gut feeling is that the sound is quite dramatically different to that which I would expect from a normal amplifier, and I don't see that it is likely to be result of the fact that it is class D (Class T is really a marketing name - its a switching amp that shuffles the carrier frequency around and compensates for switching times - nothing very unusual in that - it has been done for years in inverters to stop the ear latching on to the carrier frequency (we use much lower frequencies 2 - 16kHz) and to produce reasonable fidelity output waveforms).
All the indications to me are that Tripath have an algorithm built in to their control chip that processes the sound to achieve the soft sound people like (in fact Tripath actually refer to this at their website). One can never be sure as someone stated above - once manufacturers start processing with DSPs they can do as they wish (just look at the cheap home theatre units with their various sound effects - "hall", "church", "jazz club" etc). This is a hobby horse for me as I recently heard a top end cd player which clearly (to me anyway) does the same thing - it is well know for sounding "live" - but in doing its thing it kills attack and makes electronica sound live too - which it shouldn't!!
Any tweak I have tried with the Tripath EVM has had little influence on the basic sound. Research on the net finds generally that others have found similar results with the Be Canto EVO 200.2 - which tends to point to a character of the Tripath processing rather than a character of the particular implementation (Bel Canto make their own pcbs which are quite different to the EVM modules).
Don't get me wrong - the sound is very good and outside of direct comparisons with hi-end gear or plenty of listening experience I think most people would find it quite beguiling and quite possibly a lot of people may prefer it to other amps whcih play the game more directly down the middle.
Anyway, this is just my experience in my set up. I have no barrow to push, except having invested the money in the kit I would rather have liked the new amp to be replacing my Plinius!
Look forward to comments/feedback/experience/suggestions from others!
MurrayP
Like the others above I have been interested to follow recent developments in switching amps. Tripath and amplifiers using Tripath technology have had great press - and the evm modules are reasonably priced so I decided to give one a go.
Its summer here in NZ and despite a cold summer, 1kW of class A from a Plinius SA250 in my lounge is a bit much, so I though maybe I could try a Class D amp and maybe oust the Plinius and save a few bucks on the way past. My set up is not bad, SACD, TT, good valve pre, SA250 and N801's - and is going rather nicely (at last!). So I'm in a very good position to compare results from the Tripath amp and the Plinius (which I find increasingly hard to fault).
Just to add interest my profession involves me with design of very high power class D amplifiers (to about 750kW) - better known as inverters. The techniques of these are completely similar to those used in making class D work well - at least from an electrical engineering perspective.
I had little difficulty in getting the EVM module going (forget the number but it’s the largest one - about 300+W into 8 ohms). For the sake of peace of mind I fitted the speaker protection components which Tripath leave off the big module (I'm not running it near full power).
The result is a very "nice" sound. Very smooth, nothing offensive makes cds and records that are unlistenable through the Plinius quite pleasant by taking the harshness away. Unfortunately this is definitely a filtering process and the life and energy (air, feeling of energisation in the room) in the music go out the back door too. The bad cds I refer to are bad - it isn't the Plinius mucking them up - it just plays them as they are.
Most of the smoothing effect is in the highs. The mids seem OK but I think maybe recessed. The upper bass is not especially tight (but this may be my power supply not being big enough - I'll borrow 47kuF and add that tomorrow and see what difference it makes). My 801's need very well controlled bass or the 15inch woofers take over the sound - they sound relatively boomy with the Tripath amp.
I've incorporated all tweaks I could find on the net - except input transformers (but I have wound the input coax cable around large common mode cores appropriate for rf suppression at the frequencies used in the amp module).
I'm open to any suggestions as to how to get better sound out of the amp. Please let me know your thoughts!
My gut feeling is that the sound is quite dramatically different to that which I would expect from a normal amplifier, and I don't see that it is likely to be result of the fact that it is class D (Class T is really a marketing name - its a switching amp that shuffles the carrier frequency around and compensates for switching times - nothing very unusual in that - it has been done for years in inverters to stop the ear latching on to the carrier frequency (we use much lower frequencies 2 - 16kHz) and to produce reasonable fidelity output waveforms).
All the indications to me are that Tripath have an algorithm built in to their control chip that processes the sound to achieve the soft sound people like (in fact Tripath actually refer to this at their website). One can never be sure as someone stated above - once manufacturers start processing with DSPs they can do as they wish (just look at the cheap home theatre units with their various sound effects - "hall", "church", "jazz club" etc). This is a hobby horse for me as I recently heard a top end cd player which clearly (to me anyway) does the same thing - it is well know for sounding "live" - but in doing its thing it kills attack and makes electronica sound live too - which it shouldn't!!
Any tweak I have tried with the Tripath EVM has had little influence on the basic sound. Research on the net finds generally that others have found similar results with the Be Canto EVO 200.2 - which tends to point to a character of the Tripath processing rather than a character of the particular implementation (Bel Canto make their own pcbs which are quite different to the EVM modules).
Don't get me wrong - the sound is very good and outside of direct comparisons with hi-end gear or plenty of listening experience I think most people would find it quite beguiling and quite possibly a lot of people may prefer it to other amps whcih play the game more directly down the middle.
Anyway, this is just my experience in my set up. I have no barrow to push, except having invested the money in the kit I would rather have liked the new amp to be replacing my Plinius!
Look forward to comments/feedback/experience/suggestions from others!
MurrayP