Great sounding for one listener may be crap sounding for another. Using such subjective criteria for amp search is not a good idea. After deciding on the amp typology, try something more objective such as distortion level below ##% or power output and impedance numbers.
Sure. I’ll have to dig the map out, i did not draw it. The schema (when it comes) doe snot show the CCS on the bottom of the LTP and does not show that there are no electrolytic caps in the entire amp.
Loosely based on Eli Duttan’s El Cheapo built on a Scott EL84 PP donor
dave
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Flaxxer, I have a VTA ST120 I built about 4 years ago and like it. It has some compromises since it is stuffed into a ST70 chassis. Main issue I see is the tube rectification, it doesn't really provide enough current for the increased output. After the first 5AR4 failed I went to silicon diodes - that brings another set of issues that then need to be addressed. I've enyoyed modifying the amp but it's been an adventure. Here are the things I've done to it so far:
I think kodabmx's approach could be a great way to go if you want a platform to tinker and improve on.
- Solid state rectification and used 5V heater winding as a primary buck
- Mosfet softstart/capacitance mulitplier on B+ (removed UL/Triode switches and wiring for some more room in the chassis, wired permenant UL)
- Autobias board
- Isolated driver board from chassis (nylon screws and standoffs) to improved grounding topology
- DC Elevated 6.3V heaters using voltage divider on B+
I think kodabmx's approach could be a great way to go if you want a platform to tinker and improve on.
This is interesting, did you use the PCBs based on the Gerber files generously provided here ;
V4lve lover's free gerbers thread.
BR,
Eric
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from the site linked just above:
The black one should be in the middle. If standard ¾” spacing, one can then just flip the double pomonasa around to go from 4 to 8.
dave
The black one should be in the middle. If standard ¾” spacing, one can then just flip the double pomonasa around to go from 4 to 8.
dave
I just finished building a VTA ST120....Simply amazing product for the money....Fantastic sounding amp....Using a Schitt Saga preamp, Schiit Modi and Schitt Loki with a Bluesound Node2i for a source.....Speakers Magnapan MMGs, KEF 103.2, B&W DM601, ELAC 2.0 / 6.2 and C-Notes....All with B&W Subwoofer....All sound amazing. Was using a Cambridge Audio Azur 840 or a Yamaha M45......This amp blows them all away!
I went with the optional Relay Board and Level Control.....Using a solid state rectifier with a Variac for voltage regulation....
Very happy with the results...
I went with the optional Relay Board and Level Control.....Using a solid state rectifier with a Variac for voltage regulation....
Very happy with the results...
That 16KG6 amplifier works really well, tube can be found in XXKG6 variants. 12AU7 is also plentiful.
Is playing with a friend of mine just fine. There is also a EF86 ECC83 EL84PP i there, dunno if that works, but im pretty confident it will.
I have about 4 more amplifier designs at hand, for bigger power stuff as well. But you'd have to convince me to share the gerbers of those.
I have yet to post the updated version of the UniversalHV PCB : REV3
Cheers,
V4lve.