Well well well. This is a bit of a surprise all round! Firstly I should state that my Sonic Impact has R1 & R2 replaced by quality resisters into auricaps, then straight to the output. Also a panasonic FC replaces the central cap on the board, and wiring is all 24g solid copper and all wires have been upgraded from the board. There's a Rothwell course and fine stepped attenuator onboard and gold phonos and binding posts, and its in a wooden jewelery box with aluminium foil glued to the interior for protection from all those airborn nasties. The amp is powered by a 18Ah SLA battery and has had about 80 hrs burnin.
My system consists of rebuilt Lenco GL75 turntable with Origon Live Silver arm and Denondl103r cartridge, into stock Ear 834p phono, then Tube Technology Seer pre and homemade SET monoblocks built on a Leak tl12+ chassis with the leak transformers,, the configeration and tubes of which I'm ignorent of, but which is far superior to my previous amps, Leak tl12+'s rebuilt by Len Gregory, aka "the Cartridge Man". 24g Solid silver wire to One Thing Audio rebuilt Quad esl57's complete the system.
After no burn-in I put the S Impact into my system and was dissapointed for all the reasons you can imagine. Now after 80 hours burn in things have changed considerably. Wow! Firsly I need to say that the Sonic imact direct to phonostage using its stepped attenuator for volume was massively better than when using the Tube technology pre. With the latter, it is still frankly awful, with instruments hopelessly distorted into a cartoonlike facsimile of their normal selves, with percusion and bass receded and dull. However, on its own the Sonic Impact is now dangerously close to my SET's! I hesitate because its that close!. Bass feels slightly smaller possibly, and less defined, and percusion is slightly less sharp with less air and shimmer in the cymbals, and there's still a tiny bit of harshness to the treble. However, where this little wonder still definitely loses to the SET is in musicality, in swing, and in the "body" and organic timbre that make you feel the instrument, the player and his emotion, and in that lilt that moves you, and washes through your body as you listen, and makes me smile. The one proviso to all this is that the Sonic Impact isnt too far away, its disturbingly close. Frankly its surpassed my expectations totally. It makes me wonder bigtime about the Charlize, the UCD180 and the chipamps, and about the SMPS bought from Nuuk that I haven't wired up yet, and which Nuuk says improves things a lot. Also, I'm aware that i'm testing it in harsh conditions with the Quads, which it does drive rather well though, with far more power than the stock S Impact! I can well understand how John May prefers it to his modded Quad 303. I own a Quad 306 which i love, and has bettered modern amps at £2500 in showrooms, but i dont think it is quite in the Sonic impact's class on my system.
I now must run it in for another 50 or so hours and review the situation. I also have become more and more aware of "Synergy" of late, and can only say this is how it sounds in my system. The one strange thing was that a £1500 valve preamp ( I think thats what it cost new) that is fantastic with the SET's just didnt fit with it at all.
I hope this mini review is of interest, it certainly is to me, and i shall add to it shortly. Thanks, david
My system consists of rebuilt Lenco GL75 turntable with Origon Live Silver arm and Denondl103r cartridge, into stock Ear 834p phono, then Tube Technology Seer pre and homemade SET monoblocks built on a Leak tl12+ chassis with the leak transformers,, the configeration and tubes of which I'm ignorent of, but which is far superior to my previous amps, Leak tl12+'s rebuilt by Len Gregory, aka "the Cartridge Man". 24g Solid silver wire to One Thing Audio rebuilt Quad esl57's complete the system.
After no burn-in I put the S Impact into my system and was dissapointed for all the reasons you can imagine. Now after 80 hours burn in things have changed considerably. Wow! Firsly I need to say that the Sonic imact direct to phonostage using its stepped attenuator for volume was massively better than when using the Tube technology pre. With the latter, it is still frankly awful, with instruments hopelessly distorted into a cartoonlike facsimile of their normal selves, with percusion and bass receded and dull. However, on its own the Sonic Impact is now dangerously close to my SET's! I hesitate because its that close!. Bass feels slightly smaller possibly, and less defined, and percusion is slightly less sharp with less air and shimmer in the cymbals, and there's still a tiny bit of harshness to the treble. However, where this little wonder still definitely loses to the SET is in musicality, in swing, and in the "body" and organic timbre that make you feel the instrument, the player and his emotion, and in that lilt that moves you, and washes through your body as you listen, and makes me smile. The one proviso to all this is that the Sonic Impact isnt too far away, its disturbingly close. Frankly its surpassed my expectations totally. It makes me wonder bigtime about the Charlize, the UCD180 and the chipamps, and about the SMPS bought from Nuuk that I haven't wired up yet, and which Nuuk says improves things a lot. Also, I'm aware that i'm testing it in harsh conditions with the Quads, which it does drive rather well though, with far more power than the stock S Impact! I can well understand how John May prefers it to his modded Quad 303. I own a Quad 306 which i love, and has bettered modern amps at £2500 in showrooms, but i dont think it is quite in the Sonic impact's class on my system.
I now must run it in for another 50 or so hours and review the situation. I also have become more and more aware of "Synergy" of late, and can only say this is how it sounds in my system. The one strange thing was that a £1500 valve preamp ( I think thats what it cost new) that is fantastic with the SET's just didnt fit with it at all.
I hope this mini review is of interest, it certainly is to me, and i shall add to it shortly. Thanks, david
Cool review! Those Quad panels are hard to dirve and can realy give an amp a work out. I've built class A solid state amps that sounded much better than SETs on the Quads. They both sounded worlds better than a stock 303 or the sorry *** 405. =)
It is amazing to think that the little Triapath chip can drive those monster panels. Interesting about the preamp, too.
This should encourge you to move up to one of the better boards, Charlize, AMP6, Fenice, etc.
Keep us posted . Congratulations on a succsessful project.
It is amazing to think that the little Triapath chip can drive those monster panels. Interesting about the preamp, too.
This should encourge you to move up to one of the better boards, Charlize, AMP6, Fenice, etc.
Keep us posted . Congratulations on a succsessful project.
Hi Gilbodavid / everyone!
Glad to hear you're still happy with the T-amp. Nice review. I actually have a TA2020 amp from autocostruire, and although it goes louder there's something missing from the performance in comparison with the modded SI T-amp. Mind you I'm using the TA2020 as a power-amp, and using a passive 100k Alp blue in a box, so perhaps I need to try it with a 50k pot like I use with my modded SI T-amp. Like you I've also tried both with a valve pre-amp (Ming-da MC-7R) but felt this coloured the sound a little and prefer it with just the pot. Next stage for me is to try a stepped attenuator
Had a bit fo a conflict on interests with these Tripath chip amps to be honest. I recently had to write a review of a Class AB amp (name with held to protect the innocent - haha) which cost £1599. This was driving a pair of Mission e82 floorstanders which cost approx. £1600. Well frankly my modded SI T-amp bested this without much trouble. It's quiet surreal to look at this tiny box driving these huge speakers! AMAZING that they can drive Quad ESL57s as well!!! Really has turned my thinking about system hiearchy around, and value for money of course. How can I give amps a good review from here on in when you can get THIS level of performance for under £100?!? It's a tough one!.... Alot of the mags seem to be ignoring these amps altogether to avoid upsetting the status quo I guess...?
I received two SMPS power supplies from NUUK (thanks ) last week, so I will try those out in the coming week and see if that improves an already great sound. I might also try the Fernice board as I think that chip is my favourite judging by my preference for the SI T-amp.
Cheers!
- John
Glad to hear you're still happy with the T-amp. Nice review. I actually have a TA2020 amp from autocostruire, and although it goes louder there's something missing from the performance in comparison with the modded SI T-amp. Mind you I'm using the TA2020 as a power-amp, and using a passive 100k Alp blue in a box, so perhaps I need to try it with a 50k pot like I use with my modded SI T-amp. Like you I've also tried both with a valve pre-amp (Ming-da MC-7R) but felt this coloured the sound a little and prefer it with just the pot. Next stage for me is to try a stepped attenuator
Had a bit fo a conflict on interests with these Tripath chip amps to be honest. I recently had to write a review of a Class AB amp (name with held to protect the innocent - haha) which cost £1599. This was driving a pair of Mission e82 floorstanders which cost approx. £1600. Well frankly my modded SI T-amp bested this without much trouble. It's quiet surreal to look at this tiny box driving these huge speakers! AMAZING that they can drive Quad ESL57s as well!!! Really has turned my thinking about system hiearchy around, and value for money of course. How can I give amps a good review from here on in when you can get THIS level of performance for under £100?!? It's a tough one!.... Alot of the mags seem to be ignoring these amps altogether to avoid upsetting the status quo I guess...?
I received two SMPS power supplies from NUUK (thanks
) last week, so I will try those out in the coming week and see if that improves an already great sound. I might also try the Fernice board as I think that chip is my favourite judging by my preference for the SI T-amp.Cheers!
- John
Nuuk said:
... it's interesting to hear that the SI T-AMP can drive those Quad 57's! Now if only they can add the 'musicality' factor to the class-T's .....
I have been using the stock Autocostruire 2020 daily since July to drive my Quat 63's. Previously I was using the little SI with the intention of modding it, but when the Autocostruire appeared, I decided to go for it as it has a bit more output power. It is truly amazing that these amps are able to drive electrostatics. I also have a B&W passive sub wired in parallel with the '63's to improve bass - one 2020 drives all!
Maybe not the right forum, but has anyone tried the newly released Heresy tube/mosfe preamp released by AudioDigit / Autocostrurie? Will it add that 'musicality' that we all seem to crave?
CambshireGordon
Re: Imput impdeance
Right! And that's mostly because of R01 & R02. When modifying we generally take those out or bypass them. Input impedance should then be about 22K or 33K depending on your new input resistors.
Thus you could use 2.0uF (or maybe even 1uf) without phase problems. If you don't use the amp full range, i.e. with a sub, you could get away with 0.2uF
Panelhead said:
Right! And that's mostly because of R01 & R02. When modifying we generally take those out or bypass them. Input impedance should then be about 22K or 33K depending on your new input resistors.
Thus you could use 2.0uF (or maybe even 1uf) without phase problems. If you don't use the amp full range, i.e. with a sub, you could get away with 0.2uF
Hi Panomaniac,
Have you , or anyone else tried replacing the 100pf filtering caps before the input caps after modding. I am trying different values between 22pf and 220pf between pre input cap and ground, but can,t really tell what is happening. I thought it would roll of the treble but it is probably boosting and cutting all over the frequency.
Is there a calculation for the effect?
Thanks for all your web site help, Barry..
Have you , or anyone else tried replacing the 100pf filtering caps before the input caps after modding. I am trying different values between 22pf and 220pf between pre input cap and ground, but can,t really tell what is happening. I thought it would roll of the treble but it is probably boosting and cutting all over the frequency.
Is there a calculation for the effect?
Thanks for all your web site help, Barry..
The 100pF cap and the inductor are meant to drain off some of the RF that may be present on the input.
At 20kHz the cap would have an impedance of about 80K ohms, so it could cause a little high end roll off in the audio band, though not much. If you are using a 22k input resistor the 100pF would pull 20Khz down by about 2dB.
If I knew the value for the inductor, we could calculate the -3dB point. But I don't. Might be worth figuring out, it's likely to be a pretty small value.
At 20kHz the cap would have an impedance of about 80K ohms, so it could cause a little high end roll off in the audio band, though not much. If you are using a 22k input resistor the 100pF would pull 20Khz down by about 2dB.
If I knew the value for the inductor, we could calculate the -3dB point. But I don't. Might be worth figuring out, it's likely to be a pretty small value.
Hi Panomaniac,
I am useing the same input layout as on your web site, 36k input resistors, 2.2uf caps and 47k across a 47k pot. I am trying the caps in parallel with the 47k resistor with no inductors.
If i use a 1000pf cap there is a noticable roll off.
On tripath cct the inductors are listed as: Ferrite Bead FBM2125 BEAD CORE 4A 100 MHZ. Does this mean anything?
Cheers..
I am useing the same input layout as on your web site, 36k input resistors, 2.2uf caps and 47k across a 47k pot. I am trying the caps in parallel with the 47k resistor with no inductors.
If i use a 1000pf cap there is a noticable roll off.
On tripath cct the inductors are listed as: Ferrite Bead FBM2125 BEAD CORE 4A 100 MHZ. Does this mean anything?
Cheers..
Hello Audio1st,
I don't know what the specs are on the ferrite bead, and we don't know what bead Sonic actualy used. The beads are rated at an impedance (in ohms) at 100MHz. The impedance at audio frequncies is pretty much nil.
Yeah, you should certainly hear roll off with a 1000pF (1nF) cap - it's 10X too big. I guess your -3dB roll off would be at ~4800Hz. You would certainly hear that!
As for the input topology, you can remove the 47K resistor across the inputs. Have a listen to it both ways. Your source may like the higher impedance (no extra resistor). Some sources won't care, others will sound better. You'll have to try it and see/hear.
I don't know what the specs are on the ferrite bead, and we don't know what bead Sonic actualy used. The beads are rated at an impedance (in ohms) at 100MHz. The impedance at audio frequncies is pretty much nil.
Yeah, you should certainly hear roll off with a 1000pF (1nF) cap - it's 10X too big. I guess your -3dB roll off would be at ~4800Hz. You would certainly hear that!
As for the input topology, you can remove the 47K resistor across the inputs. Have a listen to it both ways. Your source may like the higher impedance (no extra resistor). Some sources won't care, others will sound better. You'll have to try it and see/hear.
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