This is a self-bias amplifier that allows you to replace beam tubes and pentodes from 6L6GC to KT170 without any adjustments.
Equipped with an output transformer from Hashimoto Electric, a proud Japanese manufacturer, and a V-Cap coupling capacitor, this lavish upgrade promises high performance and sound quality that far exceeds the original model.
Maximum output is 40W for KT88 and 45W for KT170, and it operates in Class A at regular levels, with a focus on sound quality.
This is a high-cost performance model that allows you to enjoy the essence of Japan quality, with a high signal-to-noise ratio, wide frequency response, and excellent damping characteristics.
SV-P1616D/VK Pentode Power-amplifier
Hashimoto version HW-40-5 kit 120V/240V
NO Volume Pot
Point to Point assembly
The production version will get rid of the volume port and replace the stock opt to Hashimoto H40-5
KT170×4 ECC81/12AT7×2 ECC82/12AU7×2 ※Tube set is an option
Rated output: UL connection (Class A operation up to 50% of rated output)
（8Ω、THD：10%）
KT170 45W+45W
KT150 37W+37W
KT120 37W+37W
KT88 35W+35W
EL34 33W+33W
KT66 25W+25W
6L6GC 22W+22W
Frequency reponse ：5Hz～150kHz(1W/8Ω/-3dB)
Gain：27～29dB（8Ω）
size in mm：W365×D300×H190
You will notice that the output transformer has been replaced by Hashimoto HW-40.
All aeesembled version be will instaled with 4X Vcap ODAM coupling caps
PRE-ORDER Pricing
KIT $2,150 (point to point kit)
Assembled $2,750 (Made and Assembled in Japan with 4 VCAPs ODAM)
TUBE SET EXTRA
It would be premature to think that anyone can just change the OPT... The output transformer affects the overall characteristics as much as a car engine. In cases such as a single triode with no feedback, it may be possible to replace it by checking the impedance and core capacity, but in the case of a push-pull amplifier with a large amount of feedback, in the worst case scenario, the amplifier may oscillate and be damaged, so careful consideration in advance and detailed measurements after replacement are required.The original output transformer is a custom-made product (made in Japan) optimized for the SV-P1616D and has KNF (cathode NF) windings, but the OPT to be installed this time does not have KNF windings. NFB is established based on the delicate balance of the amplifier, so the design is very delicate and design changes are required.
According to the report of the craftsman who was commissioned to make the prototype, the default NF resistor and phase compensation capacitor capacitance caused oscillation outside the audible range. This is something that cannot be detected by ear and can only be detected by measurement, so special care is required. As a result, integral compensation was added to the secondary side of the OPT to ensure stability and the project was completed.
I accept preorder
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Hi what's the output power? Do it have 4ohm speaker output? I am looking for a powerful push-pull amp to Gamut RS7, they are 4ohms.
SV-P1616D / Multipole tube (115V, Hashimoto version) Will be available in early 2025
Nov. 24, 2024 Mr Ohashi's Blog (Google Translation)As of yesterday, the pre-export shipment inspection of the SV-S1616D / 300B was completed, and the inspection of the SP-P1616D / Multi-electrode (115V, Hashimoto version) began today.
The primary craftsman's self-inspection, the second, the assembly inspection and re-measurement by another craftsman, and the tertiary (final) inspection are mine. Checking from a different perspective than checking three times by the same person not only greatly reduces the number of surprises, but also gives me a great opportunity to learn the high skills of craftsmen. It's like I'm learning every day.
This is the export version. The input volume has been removed at the importer's request.
The KT170 is shown in the photo, but as with the domestic version, the feature of being able to use a wide variety of output tubes has been preserved.
Internal. It has the same V-Cap as the overseas version of the S1616D. Since the output transformer has been replaced by Hashimoto, it is basically the same circuit as the domestic version, except that a Zobel filter (= constant resistance network, that is, constant impedance circuit) is added to the secondary side.
In addition, the speaker terminal has been changed to WBT type.
Speaking of which, after yesterday's entry-up, I received an inquiry asking "Can I order the domestic version at Hashimoto?" I thought that it was basically an overseas exclusive, but if the number of cases is collected to a certain extent, there is a possibility that we can accept it on a special order. Since it is practically difficult to prepare a manual separately, there is a high possibility that it will be only assembled on behalf of the craftsman, but if you can secure the man-hours of the craftsman, you may be able to accept it on a made-to-order basis.
Victor,
Great work and a neat project.
Did he try local, plate-to-plate feedback instead of the KFB or does the design no longer employ the KFB? Plate to plate would be a better scheme as it’s the shortest fb scheme and delivers lower output impedance, wider bandwidth and you can avoid the out of audio band problems which do in fact influence what we hear. I’ve used plate-plate on very difficult oscillation designs and avoided all of it.
Great work and a neat project.
Did he try local, plate-to-plate feedback instead of the KFB or does the design no longer employ the KFB? Plate to plate would be a better scheme as it’s the shortest fb scheme and delivers lower output impedance, wider bandwidth and you can avoid the out of audio band problems which do in fact influence what we hear. I’ve used plate-plate on very difficult oscillation designs and avoided all of it.
Hi Victor,
Can you tell me the power output or range depending on the tubes of this amp.
Can you compare the instruction manual with Elekit's in terms of comprehensiveness.
Thanks,
Can you tell me the power output or range depending on the tubes of this amp.
Can you compare the instruction manual with Elekit's in terms of comprehensiveness.
Thanks,