MartinT
29-06-2011, 19:09
Just how much difference can a step-up transformer make? After all, the CineMag step-up transformers I’ve been using are not too shabby and are well regarded in the forums as a bit of a bargain. So can a SUT make enough difference to justify spending any more? Read on to find out.
Hashimoto
Hashimoto are a Japanese transformer manufacturer, originally formed from Sansui employees when that company decided to cease production of transformers in-house. The best employees moved over to Hashimoto and continued their great work in designing and selling transformers, much of it initially going back to Sansui. It was said that the custom hand-wound transformers provided by Hashimoto were the secret to the success of the revered Sansui AU-111 valve amplifier from 1965. When Sansui closed their doors in 2001 as a manufacturer, Hashimoto had established their business selling high grade audiophile transformers as OEM products.
Choir Audio
John Parker, of Choir Audio, builds complete step-up units using some of the best transformers in the business, including the aforementioned CineMags and Hashimotos. He has been selling the SUT-H based on the Hashimoto HM3 transformers and is now the first manufacturer to build a complete unit, the SUT-H7, based on the new flagship Hashimoto HM7 transformers.
The SUT-H7 is built using ‘six nines’ OFC silver-plated copper wire with Teflon insulation. Mine is finished with Cardas phono sockets, but WBT can be specified as an alternative. The unit is substantially cased in a black finish and is quite large as SUTs go, weighing 2kg.
Choir Audio built my SUT-H7 to order and despatched it across the Atlantic within a couple of weeks. Communications from John have been excellent at every stage of the order process and he was a delight to deal with.
http://www.mtc.me.uk/images/ChoirSUTH7_1.jpg
Switches & Loading
There are switches for each channel providing loads of either 2-7 ohms with +29dB gain or 7-40 ohms with +23dB gain. As I found out, it’s best not to get too hung up on the loading specifics for a given cartridge and try them both out. For example, an AT-33PTG has a coil impedance of 10 ohms but requires a load impedance of “greater than 100 ohms”. This would suggest that I should use the low gain setting, but in fact high gain position sounded better. The Shelter 5000’s loose interpretation of ‘instructions’ suggests a step-up load of 20-40 ohms. Despite this, both cartridges sounded best in the 2-7 ohm setting.
The recommended loading impedance for the SUT-H7 is 47k ohms, the standard for phono preamps. I set my Whest preamp for this load and a gain of 40dB. This latter was decided on as I preferred the SUT-H7 in the high gain position and the Whest clipped when set for 50dB gain, so 40+29=69dB overall gain suited my system.
The more I experiment, the more I come to the conclusion that higher gain in the SUT and correspondingly lower gain in the phono preamp is best for sound quality, so this is how I tend to set my system up these days.
Why Use a Transformer?
I’m aware that my Whest Audio PS.30R phono preamp is capable of taking low output MC cartridges directly, and has flexible loading and gain controls for just this purpose. However, the whole reason for the existence of step-up transformers, and their apparent complexity due to yet another device introduced into the replay chain, is that they sound so incredibly vivid and dynamic when compared with active MC inputs. They also don’t generate much additional noise due to a lack of any active components. I believe that impedance matching is the key; furthermore, a transformer is able to utilise the whole energy output of the cartridge, which is generates high current at very low voltage into a higher voltage signal suitable for a standard phono stage. A phono preamp’s MC stage throws away the cartridge’s current generation (with the notable exception of the Dynavector’s P-75 phono enhancer mode) and starts from a tiny voltage. It is this whole energy preservation in a SUT, something top end MC cartridges have in abundance, that creates such excitement and dynamic prowess in their music making and sets high end vinyl playback aside from any other source.
Cabling
I connected the silver Dynavector arm cable into the SUT-H7 and then a 0.5m length of Mark Grant G2000HD from there to the Whest phono stage. The rest of the system uses Kimber Select balanced interconnects and speaker cables.
Sound
John recommended 30-50 hours of running-in time before the SUT-H7 would give of its best. Putting the SUT-H7 into circuit in place of the CineMags, I was immediately confronted with explosive dynamics and more dynamic contrasts than I’ve frankly heard in any but the most high end horn systems. This was accompanied by wider soundstage and far more precise placement of instruments than I am used to. Surface noise was very low and pops and clicks were banished to virtually inconsequential on most of my records.
There is greater depth, not in the front-to-back dimension but in how music stands out from the background. Everything is more out of the box – solid replay right there, enough to reach out and touch.
Difficult but well-known tracks like ‘Whole Lotta Love’ from Led Zeppelin II and ‘With or Without You’ from U2’s The Joshua Tree sprung into life with a zest and vividness that had me laughing out loud.
‘And I Stoned Me’ on Van Morrison’s Moondance can sound a dreadful mess on many systems. His penetrating vocals are a constant but what impressed me were the drums brought forward in the mix and the lifting of the whole piece into something resembling a live performance. Next up, another difficult track is ‘Go Home, Girl’ from Ry Cooder’s Bob Til You Drop. This very early digital recording can sound flat and two dimensional but was a revelation through the SUT-H7 using the Shelter 5000 cartridge. Clive Gregson and Christine Collister’s Mischief is recorded a little hot and up-front, but again strands of the music were separated out and the whole thing sounded vivid and alive.
Trying some more classic tracks, ‘Moving’ from Kate Bush’s The Kick Inside brought her voice right out stage front, yet the drums and cymbals were also projected in typical late 1970s style. From the same era, Joan Armatrading’s eponymous album leaves all others for dead, certainly on this reckoning with stunning acoustic guitar and, again, highly projected and expressive voice.
One of my favourite tests is pretty much the whole of side 1 of Santana’s Abraxas. The lead-in ‘Singing Winds, Crying Beasts’ with its gentle piano and incredibly realistic wind chimes didn’t prepare me for the lengthy, hugely penetrating note from Carlos’ Strat, once again challenging my volume setting. Further in, the stage-right percussion work in ‘Oye Como Va’ was simply fabulous.
Many more songs reinforced my complete enjoyment of the SUT-H7’s contribution to the new sound of my system. Switching from the AT-33PTG to the Shelter 5000 just upped the level again in all aspects: midrange transparency, treble sweetness and extension and a sense of swell that remained ever dangerous. The sound settled down after about 50 hours of use, as John predicted.
http://www.mtc.me.uk/images/ChoirSUTH7_3.jpg
Conclusions
If anyone had told me before receiving the SUT-H7 that I would, as a result, rework my phono system hierarchy I would have been surprised. But here it is: turntable > arm > SUT > cartridge > phono amp. The Choir Audio SUT-H7 has unlocked the potential of my already very capable front end in a way that no cartridge, and I mean no cartridge, could ever have achieved. I feel that, after some 35 years of system building, I have finally achieved high end sound. The SUT-H7 is that good.
I wasn’t sure what to expect when I read Choir Audio’s warning “Please make sure that your source is up to the task as the HM-7 is very revealing and will uncover any weak links in your source components”. I needn’t have worried. In the context of my overall system, and understanding that some will dispute my use of the word, the SUT-H7 is an absolute bargain and has given me more musical nirvana than any other component change could have achieved.
Test system
Heavily modified Technics SL-1210 turntable with Dynavector DV-507II arm, Shelter 5000 and Audio Technica AT-33PTG cartridges. Whest PS.30R phono preamp, Pass Labs XP-20 preamp and Chord SPM-1200E power amp. Usher Dancer Be-20 speakers. PS Audio Powerplant Premier mains regenerator.
Competitive equipment: Bob’s Devices CineMag SUT, Whest PS.30R (direct in).
Price $1,499
Available direct from Choir Audio, USA:
http://www.choiraudio.com/
Hashimoto
Hashimoto are a Japanese transformer manufacturer, originally formed from Sansui employees when that company decided to cease production of transformers in-house. The best employees moved over to Hashimoto and continued their great work in designing and selling transformers, much of it initially going back to Sansui. It was said that the custom hand-wound transformers provided by Hashimoto were the secret to the success of the revered Sansui AU-111 valve amplifier from 1965. When Sansui closed their doors in 2001 as a manufacturer, Hashimoto had established their business selling high grade audiophile transformers as OEM products.
Choir Audio
John Parker, of Choir Audio, builds complete step-up units using some of the best transformers in the business, including the aforementioned CineMags and Hashimotos. He has been selling the SUT-H based on the Hashimoto HM3 transformers and is now the first manufacturer to build a complete unit, the SUT-H7, based on the new flagship Hashimoto HM7 transformers.
The SUT-H7 is built using ‘six nines’ OFC silver-plated copper wire with Teflon insulation. Mine is finished with Cardas phono sockets, but WBT can be specified as an alternative. The unit is substantially cased in a black finish and is quite large as SUTs go, weighing 2kg.
Choir Audio built my SUT-H7 to order and despatched it across the Atlantic within a couple of weeks. Communications from John have been excellent at every stage of the order process and he was a delight to deal with.
http://www.mtc.me.uk/images/ChoirSUTH7_1.jpg
Switches & Loading
There are switches for each channel providing loads of either 2-7 ohms with +29dB gain or 7-40 ohms with +23dB gain. As I found out, it’s best not to get too hung up on the loading specifics for a given cartridge and try them both out. For example, an AT-33PTG has a coil impedance of 10 ohms but requires a load impedance of “greater than 100 ohms”. This would suggest that I should use the low gain setting, but in fact high gain position sounded better. The Shelter 5000’s loose interpretation of ‘instructions’ suggests a step-up load of 20-40 ohms. Despite this, both cartridges sounded best in the 2-7 ohm setting.
The recommended loading impedance for the SUT-H7 is 47k ohms, the standard for phono preamps. I set my Whest preamp for this load and a gain of 40dB. This latter was decided on as I preferred the SUT-H7 in the high gain position and the Whest clipped when set for 50dB gain, so 40+29=69dB overall gain suited my system.
The more I experiment, the more I come to the conclusion that higher gain in the SUT and correspondingly lower gain in the phono preamp is best for sound quality, so this is how I tend to set my system up these days.
Why Use a Transformer?
I’m aware that my Whest Audio PS.30R phono preamp is capable of taking low output MC cartridges directly, and has flexible loading and gain controls for just this purpose. However, the whole reason for the existence of step-up transformers, and their apparent complexity due to yet another device introduced into the replay chain, is that they sound so incredibly vivid and dynamic when compared with active MC inputs. They also don’t generate much additional noise due to a lack of any active components. I believe that impedance matching is the key; furthermore, a transformer is able to utilise the whole energy output of the cartridge, which is generates high current at very low voltage into a higher voltage signal suitable for a standard phono stage. A phono preamp’s MC stage throws away the cartridge’s current generation (with the notable exception of the Dynavector’s P-75 phono enhancer mode) and starts from a tiny voltage. It is this whole energy preservation in a SUT, something top end MC cartridges have in abundance, that creates such excitement and dynamic prowess in their music making and sets high end vinyl playback aside from any other source.
Cabling
I connected the silver Dynavector arm cable into the SUT-H7 and then a 0.5m length of Mark Grant G2000HD from there to the Whest phono stage. The rest of the system uses Kimber Select balanced interconnects and speaker cables.
Sound
John recommended 30-50 hours of running-in time before the SUT-H7 would give of its best. Putting the SUT-H7 into circuit in place of the CineMags, I was immediately confronted with explosive dynamics and more dynamic contrasts than I’ve frankly heard in any but the most high end horn systems. This was accompanied by wider soundstage and far more precise placement of instruments than I am used to. Surface noise was very low and pops and clicks were banished to virtually inconsequential on most of my records.
There is greater depth, not in the front-to-back dimension but in how music stands out from the background. Everything is more out of the box – solid replay right there, enough to reach out and touch.
Difficult but well-known tracks like ‘Whole Lotta Love’ from Led Zeppelin II and ‘With or Without You’ from U2’s The Joshua Tree sprung into life with a zest and vividness that had me laughing out loud.
‘And I Stoned Me’ on Van Morrison’s Moondance can sound a dreadful mess on many systems. His penetrating vocals are a constant but what impressed me were the drums brought forward in the mix and the lifting of the whole piece into something resembling a live performance. Next up, another difficult track is ‘Go Home, Girl’ from Ry Cooder’s Bob Til You Drop. This very early digital recording can sound flat and two dimensional but was a revelation through the SUT-H7 using the Shelter 5000 cartridge. Clive Gregson and Christine Collister’s Mischief is recorded a little hot and up-front, but again strands of the music were separated out and the whole thing sounded vivid and alive.
Trying some more classic tracks, ‘Moving’ from Kate Bush’s The Kick Inside brought her voice right out stage front, yet the drums and cymbals were also projected in typical late 1970s style. From the same era, Joan Armatrading’s eponymous album leaves all others for dead, certainly on this reckoning with stunning acoustic guitar and, again, highly projected and expressive voice.
One of my favourite tests is pretty much the whole of side 1 of Santana’s Abraxas. The lead-in ‘Singing Winds, Crying Beasts’ with its gentle piano and incredibly realistic wind chimes didn’t prepare me for the lengthy, hugely penetrating note from Carlos’ Strat, once again challenging my volume setting. Further in, the stage-right percussion work in ‘Oye Como Va’ was simply fabulous.
Many more songs reinforced my complete enjoyment of the SUT-H7’s contribution to the new sound of my system. Switching from the AT-33PTG to the Shelter 5000 just upped the level again in all aspects: midrange transparency, treble sweetness and extension and a sense of swell that remained ever dangerous. The sound settled down after about 50 hours of use, as John predicted.
http://www.mtc.me.uk/images/ChoirSUTH7_3.jpg
Conclusions
If anyone had told me before receiving the SUT-H7 that I would, as a result, rework my phono system hierarchy I would have been surprised. But here it is: turntable > arm > SUT > cartridge > phono amp. The Choir Audio SUT-H7 has unlocked the potential of my already very capable front end in a way that no cartridge, and I mean no cartridge, could ever have achieved. I feel that, after some 35 years of system building, I have finally achieved high end sound. The SUT-H7 is that good.
I wasn’t sure what to expect when I read Choir Audio’s warning “Please make sure that your source is up to the task as the HM-7 is very revealing and will uncover any weak links in your source components”. I needn’t have worried. In the context of my overall system, and understanding that some will dispute my use of the word, the SUT-H7 is an absolute bargain and has given me more musical nirvana than any other component change could have achieved.
Test system
Heavily modified Technics SL-1210 turntable with Dynavector DV-507II arm, Shelter 5000 and Audio Technica AT-33PTG cartridges. Whest PS.30R phono preamp, Pass Labs XP-20 preamp and Chord SPM-1200E power amp. Usher Dancer Be-20 speakers. PS Audio Powerplant Premier mains regenerator.
Competitive equipment: Bob’s Devices CineMag SUT, Whest PS.30R (direct in).
Price $1,499
Available direct from Choir Audio, USA:
http://www.choiraudio.com/