tomislavkufrin

My father told me that he cannot hear anything, but i can hear a very faint hum. There is room for improvement in my heater wiring. And i need to check if my soldering of socket pins is good. Better to ignore that question, i got confused about nothing..

New tubes are in, 25V difference between + and - is gone. Works like a charm. Just for info, are there any other tube options that are not Tung Sol GTB, and not NOS?

Payment sent! Thank You.

My mind tells me carbon, but my heart tells me grounded grid/blue hawaii. In the end i was thinking to make universal psu for carbon/grounded grid combination so i can have both. I think summed, this is again closer to the T2 budget. Then someone writes that blue hawaii is somewhere in between. Is this more like different shades of grey, or T2 is really that much better?

I did not have problems balancing the driver tube plate voltages. Resistances are in 2500 +-200 ohm range. So, not to far off center. Looks like only that output tube is not matched well. Excellent, because i really like the sound

Warm, i measured 8 hours after start. Value looks stable, i did not notice it change too much. I just do not like the numbers. I did exactly that. Same offset value, it just moved to the other channel. Next time i'll just buy everything matched.

right now R+ to R- is <1V and R+ or R- to GND is <1V. And tends to stay like this. When i measure during the day R+ or R- to GND is around 0 +-3V. L+ to L- is 25, 22V, which i try to split in reference GND. Lets say L+ to GND ~= 11V and L- to GND ~= -11V. That is like a best case.

What is the maximum voltage difference you can have between output + and - of a channel? 22-25 volts is still ok, or on the high side? Whatever i do with the pots it looks like this voltage difference is just shifting, not even changing. minimum i can get is 21V. I do not have this problem on the other channel. When i tried to swap them, i could again zero the offset and +/- on the "good" tube in opposite place. There are no sound issues but i would not like to damage the headphones.

i would like to get in the group buy. for me please: 4x GRHVxxx 2x GRLV79xx 2x GRLV78xx 2x Main Board 2x miniT2 - bare boards.

the chimp is re-listening his music catalog. this forum is a bit like AA meetings. except, instead to stop, people pull you in to do more alcohol.

not the prettiest build, but i'm learning. goal was to make it work, and worry about the looks later. metal works was something new for me, you need to have good tools. these are my first two amps i have ever built. lower one is SS dynalo. edit: looks like i can upload maximum one picture(500 kb).

for the moment i will leave it and enjoy the sound. hum is almost completely gone. if i make all the modifications immediately i will have nothing to do in the following weeks. also, my girlfriend will kill me if i open the chassis one more time to tweak something. i will try go get some higher quality/new tubes also.

i used 500k and 100k what i had spare for 60V elevation. this is only for input tubes, output ones i left floating. C1 i need to buy first, after that i will try. now the hum is minimal. still present but not annoying. edit: it seems the hum disappeared after the tubes warmed up a little bit . or at least it is at the level of my pc fan.

http://deewm.com/Webcache/The_Valve_Wizard/Heater_Filament_Supplies/Heater_Filament_Supplies.html something like this(lower pic)? it is basically same like valve wizard, but with artificial centre tap. also what i found regarding separate trafo/windings.. what i understand, only separate windings are needed, not two transformers. somebody please correct me if i am wrong.

it looks like i have found a main suspect, i played around swapping tubes and i managed to get the hum on the other channel. the noise level is also a bit better in this configuration. i'll order some new tubes. definitely. i have a thing for simple stuff that work well. i think it is a very good place to start. to stop also.

ok, one more srx-plus is alive and kicking. i have managed to zero everything, but i have some annoying hum issues on left channel which i am pretty sure i did not have when i first tried the amp. even with the hum it works really nice with sr-009's ability to embed music directly into your eyes whether they are open or closed. for digital attenuator i have borrowed an idea that i like on rme adi-2 dac. volume steps are changing depending on the rotation speed of the encoder: 0.5db, 1db or 2db. maybe for tube amp this is not really needed as you would reach the volume level necessary to hear music right about the time the tubes are nice and warm. now i feel disappointed in myself that i did not impulse buy all the parts for the carbon so i have something to do until the situation with the corona virus calms down a little bit..

looking forward to trying this amp with sr-009. now i have 727, and its like looking at a really pretty girl with no tits, ass and personality.

i have some spare digital attenuator boards, and i was thinking to make one for SRX+ (i have made 10k one for SS Dynalo). is 10k ok for the digital attenuator in this case, or should i go for higher value?

i have a question. i have tried to get quote for this board, and when i have uploaded the gerber file, system detected 3 layers. i can choose between 2, 4, 6. if i were to use 2, what happens if this inner layer is discarded? or in case of 4 layer, i suppose this inner layer is then duplicated and then there are two 2-layer boards pressed together with same inner layer? thank you