I am using it on a set of 300 ohm Sennheiser HD 650 without any problems. I wish I had a little less sensitivity at the low end of the volume control, but my DAC has a rather high output level.
When I first built the kit, I picked up a few pairs of different tubes. I agree that their was very little difference between the sound of the different tubes. I heard far greater differences when running different source DACs into the unit.
The LEDs under the tubes are voltage ref. for the tube. The two others are voltage ref. for the CCS transistor. So if you run the amp in anode resistor mode it may work fine. It will be my guess that amp is not working in CCS mode?
The best guess is that you have reversed the diodes for the CCS?
You can measure voltage over the diode. If you measure 48V it indicates that diodes are reversed. Think you should measure about 3V or so over blue led if it is conducting.
The best guess is that you have reversed the diodes for the CCS?
You can measure voltage over the diode. If you measure 48V it indicates that diodes are reversed. Think you should measure about 3V or so over blue led if it is conducting.
It is working in CCS mode. I will attempt to measure the voltage across the LEDs and report back.
I didn't see them lit during the smoke test and I cannot see their light through the bottom cover vent holes. Thank you for the fast reply and help.Hi -- newbie here. I just finished this with my son today and we're in need of some troubleshooting assistance. Sound only working in one channel, and some static in other. Seems the LED1 by the side of one tube socket does not light up, all 3 other LEDs do. Same tube does not seem to warm up while the other is fine. I suspect there's a soldering problem somewhere but nothing obvious to the eye. Before I clean up and resolder all 7 tube socket connectors for that channel, is there anything else I might usefully check in case it's a mistake somewhere else in that channel? Don't have a multimeter to hand (my bad). I've experience soldering but was using this to teach my son -- nothing obvious that I can detect as a problem otherwise.
Thanks
Oscar
Thanks
Oscar
Ok, another try. Got a multimeter but am perplexed by this instruction in the manual"
"Measure the DC voltage between ground and pin 3 of each of the tube sockets. You can find ground on pin 3, or on the headphone jack nearest the front panel"
Is pin 3 ground or am I missing something? And where on the headphone jack exactly would I find the other ground? Still hoping to get this to work...
"Measure the DC voltage between ground and pin 3 of each of the tube sockets. You can find ground on pin 3, or on the headphone jack nearest the front panel"
Is pin 3 ground or am I missing something? And where on the headphone jack exactly would I find the other ground? Still hoping to get this to work...
I messed one up and asked Pete for the part number and he sent me this, Mouser 604-WP710A10QBC/D
Bill
A while ago I built the SSII headphone amp with the Raytheon tubes, and I got a LOT of distortion on my Audio Technica ATH-M50x headphones (impedance 38 Ohms). I switched the amp to CCS (Constant Current Source) for less distortion.
Then I bought the tube-rolling kits and exchanged them with Westinghouse (actually Sylvania tubes) and the distortion was somewhat better (i.e. less), but still present. Especially the vocals sound distant, echoey and distorted.
Is there something I could have done wrong? In my opinion the amp does not go very loud either. However, up until now I have been feeding it MP3's, so I could try a more HD source like CD. Any suggestions?
Then I bought the tube-rolling kits and exchanged them with Westinghouse (actually Sylvania tubes) and the distortion was somewhat better (i.e. less), but still present. Especially the vocals sound distant, echoey and distorted.
Is there something I could have done wrong? In my opinion the amp does not go very loud either. However, up until now I have been feeding it MP3's, so I could try a more HD source like CD. Any suggestions?
Maybe I should have gotten a good iron first.
Today I built the SSII, was reassured with glowing diodes, 19v on pin #3 each channel, and 17v with the tubes. I hooked up an old iPod, and...nothing. No sound.
Tomorrow I’m ordering a better soldering station and later this week I’ll be re-flowing the joints.
Any ideas from any of you, in the meantime?
Thanks!
Today I built the SSII, was reassured with glowing diodes, 19v on pin #3 each channel, and 17v with the tubes. I hooked up an old iPod, and...nothing. No sound.
Tomorrow I’m ordering a better soldering station and later this week I’ll be re-flowing the joints.
Any ideas from any of you, in the meantime?
Thanks!
Regarding my last (which was also my first) post, is is safe to assume that since I have good voltages on pin 3 of each tube that I didn't overheat the diodes? Is there a one central place that would kill each channel?
I really would like to fix this before going a few blocks north to a friend who builds his own tube amps. Before I build an amp with his guidance, I'd really like to have a little success with this project.
I really would like to fix this before going a few blocks north to a friend who builds his own tube amps. Before I build an amp with his guidance, I'd really like to have a little success with this project.
I recently built the first Starving Student Amp, but replaced the 19J6 tubes with 12SR7. Changed the resistor values and the pin layout for it as well, according to a thread I found. However, when I plug it in, the right side doesn't work, the left side experiences a constant loud noise and it crackles when I move it. The tubes and heatsinks get hot and music plays fine.
I've redone most of the joints already, but that didn't help. I don't have a tube socket however, and I'm sceptical of the solder joints there. Is there a better way of soldering tubes that doesn't require a socket? I kinda don't want to order one from china, shipping would take ages.
I'm also currently not using a metal enclosure and I've wired everything pretty much point to point. I've also connected the power ground as well as the audio ground together to the ground pin on the power jack. Could that be a problem?
I really have very little experience in things like this, so any help would be greatly appreciated.
I've redone most of the joints already, but that didn't help. I don't have a tube socket however, and I'm sceptical of the solder joints there. Is there a better way of soldering tubes that doesn't require a socket? I kinda don't want to order one from china, shipping would take ages.
I'm also currently not using a metal enclosure and I've wired everything pretty much point to point. I've also connected the power ground as well as the audio ground together to the ground pin on the power jack. Could that be a problem?
I really have very little experience in things like this, so any help would be greatly appreciated.