Input on one shunt, output on the other shunt?
Yep I remember changing my mind when soldering input/output/left/right signal paths. But forgot the groundpath.
No Look at the channels at both drawings.
Yes its a stereo diagram and who says watching one side automatically makes the other side the same.
Dodo
Glad you got it sorted. NOw tell us how the thing sounds
Thanx bud. I almost went crazy on this. Right now I simplified it to resistor CF, maybe Ill mout the chokes b4 I hit the pillow. Then everything is soldered on and off so many times so I have some fixing up to do. Pot still scrapes and its equal microphonic even hum-free.
Thanx bud. I almost went crazy on this. Right now I simplified it to resistor CF, maybe Ill mout the chokes b4 I hit the pillow. Then everything is soldered on and off so many times so I have some fixing up to do. Pot still scrapes and its equal microphonic even hum-free.
Ill make you feel better. When I hooked mine up for first time, I had singing tubes I had hooked sensing wires up at wrong point and the damn things actually sang
Feel better
Chokes are way to go after a quick listening. Right now on test rig they pick up a very small portion of hum (i had to stand a long time with the ear in the cone to decide if it was the amp or the radiator behind the bench) from nearby other iron, standing as microphones in the air, but thats fixable.
Hopefully now some tweaking ahead instead of problemshooting.
Hopefully now some tweaking ahead instead of problemshooting.
Well. I aint dead yet
Infact, I have been amusing myself by starting to fiddle with Arta. I'm ofcourse a total diaster on that to but atleast I managed to get some results.
First pic is testing my soundcards levels.
Then ofcourse I measured the 6V6, standing as it was, with a little bit of hum. Chokes 15 cm from powertrafo. Thats next graph.
Then I moved around a bit so the chokes came around 50 cm from trafo. Everything is still open and unshielded. Unfortunately the connections between SSHVs and load extended a bit, to around 15 cm. Graph 3. Still a 50 Hz problem thats plants some strange harmonics on the way. But quite a bit lower.
I have some groundingproblem still so I tested with removing yellow /green earthground from the audio circuits shielding box (that is connected with chokes. Pic 4. Look how it changes.
Yea. Its still very open and unshielded, standing on my computerdesk with screens and stuff radiating around. Look also as the highs seem to follow the highs on the soundcard.
Infact, I have been amusing myself by starting to fiddle with Arta. I'm ofcourse a total diaster on that to but atleast I managed to get some results.
First pic is testing my soundcards levels.
Then ofcourse I measured the 6V6, standing as it was, with a little bit of hum. Chokes 15 cm from powertrafo. Thats next graph.
Then I moved around a bit so the chokes came around 50 cm from trafo. Everything is still open and unshielded. Unfortunately the connections between SSHVs and load extended a bit, to around 15 cm. Graph 3. Still a 50 Hz problem thats plants some strange harmonics on the way. But quite a bit lower.
I have some groundingproblem still so I tested with removing yellow /green earthground from the audio circuits shielding box (that is connected with chokes. Pic 4. Look how it changes.
Yea. Its still very open and unshielded, standing on my computerdesk with screens and stuff radiating around. Look also as the highs seem to follow the highs on the soundcard.
Attachments
Last edited:
Only watch it not to drive large pk to pk into the card's audio input, it may not have clamping diodes for protection, watch out not to connect DC there too. Don't drive from the Wavetek cranked up and then FFT in the audio card in other words or tweak the pre when energized and hooked up to the card etc.
Yes the CF is proof for not adding gain still if a transient happens it can pass very large swing. Say a touch on input or a hot plug/unplug. You remember it passed intact the full 20V pk-pk of the Wavetek and was hungry for more. Its good to have the Zeners in general.
- Home
- Amplifiers
- Tubes / Valves
- 6V6 line preamp