Thanks very much for the info and bringing the SV128ii to my attention. I will take a look into it.
One last question about the SV-1628D, do you know the amount of global feedback used in the amp? thanks for your patience.
Hi Victor, yes that's no problem for me, I've experiences with very HighVoltage lab equipment and HV GaN and SiC devices. ( 1200, 2-3kV + high current application). Still interested to know the amount of Global Negative feedback if ther is any in the SV-1628D.
I would assume that there is no GNFB in these triode amps. Everything is very traditional.
Traditional SET designs do not use global NFB, but only the schematics can confirm it.
Hi Victor, if you have constructed the amp before, just take a look inside the amp or the manual or schematics to see if you brought a wire from the loudspeaker side of the coils back into somewhere near the 1st input tube of the amp. Another thing I like to know is what impedance was used for the output transformer? Around the 9-10k ohm or the higher 14 to 17k ohm?
Are there any reviews of the SV1628 amp? Japanese or any reviews in any language of this amp? Or do you have the contacts for the maker of the kit so I can email them for more info?
I took a look at the SV128ii it uses KT170 so I am not that interested in it
Are there any reviews of the SV1628 amp? Japanese or any reviews in any language of this amp? Or do you have the contacts for the maker of the kit so I can email them for more info?
I took a look at the SV128ii it uses KT170 so I am not that interested in it
https://isotransformers.tokyo/カタログ/
Primany is 5K for 211/845Kit .. you can pick your pice range fromthe chart
Primany is 5K for 211/845Kit .. you can pick your pice range fromthe chart
Sun Valley S1628D 211/845 w/ Hashimoto Opt Txs (see pics above a few posts from Victor)
I've been a member since 2006 but haven't posted anything in years. I have continued to build various kit projects (Audio Note, Bottlehead, WAD, Transcendent Audio, DIY Speakers, Nixie Clocks, etc.
but I am not particularly skilled in electronics). However, I wanted to share my experience with this project since Victor was very responsive/supportive and did what he said (great follow through) which has not always been my experience. Also, the kit was very well packaged, parts were well organized, and they were generally good quality components. The kit was "psychologically" challenging from the perspective of the "higher voltages" involved which I didn't have direct experience with but the directions/diagrams and schematic were clear (and in color which helped) and the couple questions I had Victor quickly clarified for me . . . the kit worked/ voltages all checked out on first switch on! I would recommend this kit for someone with prior experience with similar projects and of course good soldering skills. . . (I'm trying to convey it was more complex than my previous projects - "medium +" skills needed which is of course subjective . . .)
Since I would (likely) have this amplifier for many years I ordered the Hashimoto opt txs which were a bit expensive. . . (however, very affordable compared to my Audio Note Line, IT, and Opt Txs
). I ordered the H-30-5S from http://www.tube-amps.net/ ($850/pr plus shipping $218 to Alaska - they took about 3 weeks). I tweaked a few other things (ie "grounded" the chassis, "upgraded" a few resistors, cathode and coupling caps, added a switch to control the amount of NFB). I think Victor is doing a fabulous service to the DIY community by making Sun Valley kits available (surely a labor of love since financial motives aren't significant in the DIY business). I hope to build another project from Sun Valley down the road and look forward to interacting with Victor again . . . surely one can't have to many SET amplifiers . . .
Best Regards,
Mike
Anchorage, Alaska
Hi Mike, may I ask what’s the max voltage that can be tolerated by the Hashimoto H-30-5S? 1000V?Sun Valley S1628D 211/845 w/ Hashimoto Opt Txs (see pics above a few posts from Victor)
I've been a member since 2006 but haven't posted anything in years. I have continued to build various kit projects (Audio Note, Bottlehead, WAD, Transcendent Audio, DIY Speakers, Nixie Clocks, etc.
The kit was "psychologically" challenging from the perspective of the "higher voltages" involved which I didn't have direct experience with but the directions/diagrams and schematic were clear (and in color which helped) and the couple questions I had Victor quickly clarified for me . . . the kit worked/ voltages all checked out on first switch on! I would recommend this kit for someone with prior experience with similar projects and of course good soldering skills. . . (I'm trying to convey it was more complex than my previous projects - "medium +" skills needed which is of course subjective . . .)
Since I would (likely) have this amplifier for many years I ordered the Hashimoto opt txs which were a bit expensive. . . (however, very affordable compared to my Audio Note Line, IT, and Opt Txs
I think Victor is doing a fabulous service to the DIY community by making Sun Valley kits available (surely a labor of love since financial motives aren't significant in the DIY business). I hope to build another project from Sun Valley down the road and look forward to interacting with Victor again . . . surely one can't have to many SET amplifiers . . .
Best Regards,
Mike
Anchorage, Alaska
Also did you consider the tango FC-40-5S? And if yes, what’s reason you went with the Hashimoto?
By the way I too got the SV1628D from Victor and can say the kit is nicely packaged and instructions are very clear and detailed.
Nick
http://www.hashimoto-trans.co.jp/frame/tubecat22.pdf
https://isotransformers.tokyo/カタログ/
FC 40-5S is double the price...
https://isotransformers.tokyo/カタログ/
FC 40-5S is double the price...
Hi Nick,
I don't see the max voltage rating listed on the information I received associated with the H-30-5S txs. Below are the email contacts that will hopefully lead to getting your questions answered. I received a quick response from Isao Asakura when I inquired into cost and delivery estimates.
This was my first foray into Japanese output txs so I went with Victor's recommendation regarding Hashimoto. Someday I hope to experience other options
. I am really enjoying the amp so far with the 211 tubes. I'm waiting for the 845s to arrive. I'm looking forward to comparing the tube types and see if there's a clear preference.Mike
support@tube-amps.net
support@obsinc.us
Hi Victor, iso-tango FC-40-5S is ~ 69000 yen each. Hashimoto H-30-5S is 61000 yen. About the same price…?
Just some info that could be useful for other diy-ers
Info from iso manufacturers: The iso-tango FC-40-5S is safe for 1000V dc max, insulation tested to 2000V
From Isao who distributes the Hashimoto line, he said the H-30-5S is ok for upto 800V anything higher not recommended
Info from iso manufacturers: The iso-tango FC-40-5S is safe for 1000V dc max, insulation tested to 2000V
From Isao who distributes the Hashimoto line, he said the H-30-5S is ok for upto 800V anything higher not recommended