Thimios, it gives me association with a tank (in a good way) - a combination of power and uncompromised durability 😎
Jeff don't forget,it is one channel!
I hope to do the same with the other.😀
Valery,yes like a tank ,the housing and the internall😉
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The NS OPS has been singing in my listening room for a few hours last night but on test speakers and it sounded really good with great soundstage. I have to re-bias the output stage since I'm getting a 5 Celsius difference on the heatsinks.
Do
Do
Did you get your issues with the over-current detection ironed out? These amps don't make a lot of heat so any air movement in the room such as a register can cause a large difference in heat sink temperatures.
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TubSumo part list
Just now i see that i haven't the bom and the schematic diagrame for the TubSumo IPS.
Who can help me?
Just now i see that i haven't the bom and the schematic diagrame for the TubSumo IPS.
Who can help me?
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I tested the amplifier with a 2R load with a music source and medium to high volume and the protection was far from being close to trip... I haven’t tested the amplifier on the main speakers yet, from where it was tripping the protection. I will test this further. There is only one register in that room and it is far back but I will block it and let the amp run for a couple hours.
Nice! Mine is all assembled but not yet tested since I have to assemble the filament supply for it. You’ll probably get there first!
Ciao!
Do
If you have already IPS assembled why you not use a bench power supply for tube filament?😉
I could but I'm still testing the amplifier and making sure everything is 100% ok before I go any further. I know I'm on the slow side these days but I've been working on three amps at the same time (fixing two defective FC-100 and TGM8, assembling USSA3), plus this one. 😀
Just run the heaters on ac. Mine is this way and no hum. You could switch to regulated dc later when you get the itch to play
Hi Evanc,
I only have an 9Vac transformer so it's a little too high. I've got all the parts for the reg, just need to assemble it. I have the Vertical CFA up and running in the meantime.
Thanks
Do
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ok... So here's the reason why my left channel heatsink is 5 degrees colder... The emitter resistor show no voltage across them... Previously it was biased at 20mV but for some odd reason, nothing anymore...
I've tried centering R43 and maxing R31 and redoing the whole biasing but R31 from one end to the other doesn't make bias setting go up... Only when I have R43 to max value does it give me 5mV on emitter 0.22R... Adjusting R31 when R43 is maxed doesn't change anything... I don't know what could have gone wrong but weird... Blue LEDs still light up and music still plays fine though (only tried playing at very low level)
Any pointers?
Thanks
Do
I've tried centering R43 and maxing R31 and redoing the whole biasing but R31 from one end to the other doesn't make bias setting go up... Only when I have R43 to max value does it give me 5mV on emitter 0.22R... Adjusting R31 when R43 is maxed doesn't change anything... I don't know what could have gone wrong but weird... Blue LEDs still light up and music still plays fine though (only tried playing at very low level)
Any pointers?
Thanks
Do
As George recommends, check your VAS current of the input. This is what drives the bias spreader.
Tribute-3000,nice looking PCBs. 😉
What transformer VA,rail voltage are you using and PSU capacitors source?
Best regards,
Cambe
What transformer VA,rail voltage are you using and PSU capacitors source?
Best regards,
Cambe
I'll likely build this with +/- 56V rails and 400VA transformers with 80mF supplies / channel. It'll be a while before I actually get to this one though.