Tube headphone amp kit for $25!? - Page 3

Did you adjust your potentiometers up. Mine sounded rough the first couple of hours But I burned it in for about 30 hours and it got so loud I had to turn the potentiometers down. I'm using a ipod for a source

I've tried adjusting everything I can find. I've got the onboard potentiometers the highest they can be without distorting (which is actually pretty low, they're just a little above nothing). Any more and the sound is dirty and distorted.

So it gets louder after some hours running? I'll leave it running then and hope to see some improvement.

Matt, you gonna start smelling like solder fumes Looks a nice project, thanks sunneebear for bringing this to light

Hey I'm sorry I did not notice that you added a volume knob. I use my potentiometers for the balance and my ipods Volume control for the volume. I am running the potentiometers pretty low or i'm sure I could blow my earbuds.Could it be your volume knob itself ,did you put the volume knob in line before or after the amp. My volume adjustment is before the amp

I'm suspecting it's the potentiometer I used for the volume knob, but I checked to make sure it's wired properly and all. My volume control on the amp is after. It's wired between the output on the board and the headphone out. Would it work better if I wired it between the rca inputs and the input on the board?

what's your source

I've used my iPod with line out as well as my aune dac. In both cases it should be receiving a line level signal, I think.

ok i'm using my ipods out jack (no lod) into the amp input and I plug my earbuds into the amps output
If you hook yours up like this try to jumper out (or bypass)the volume knob and try to adjust the volume with your ipod If this works the problems with your amps volume knob

well yes, when I use the headphone out from my iPod, then the iPod dictates the volume of the output. I may try to put the volume knob before the amp tomorrow or when I have time. Or maybe not, it still gets loud enough for me as it is now, it's more just an annoyance. I appreciate your help though hipcat.

No problem let me know how it works out

I think this'll be a project that'll be a warm-down after the current AMB and Jaycar onslaught. I'll probably use it a pre-amp for my tiny amp for my DIY speakers.

Hey Squid+, I'll take my amp home tomarrow and hook my ipod lod to it to see if I get the same results. I've seen several of these amps now and I have'nt seen one with a volume control. I don't think this amp is designed to work with a line level signal. If I understand it right the line level signal has no "power" it's just a signal. I think this amp needs a amped signal to boost it. Theirs no power to really boost a line level signal if you see what I mean I think that why you need to turn up your volume so high.If I'm wrong I hope someone will set me straight. Any way I'll see what happens tomarrow and let you know.

so can you use this one with a tube socket and just test different tubes on it? Seems to mee that might give some potential

I believe it's usually preferable to use line level signals, to reduce coloration and distortion or something. I guess it could be the opposite in this case, but I'd be surprised.

I was thinking about it last night, and it seems to make good sense that the volume would reach higher levels if the volume pot was installed before the amping stage. I probably won't bother fixing it on this amp, since it's just for personal use and still reaches volumes loud enough that I wouldn't listen at. The space is small and I don't want to risk messing up something else to get this normal.

Thanks again for the help though, guys. Next amp I build, I'll put the volume control on the input side of the amping.

[edit: just thought I'd add that I moved the volume pot before the amp stage earlier today. That fixes the low volume problem, but it seems like I hear tube ringing more than before (it was nonexistant before). It's very quiet though and I can't really hear it with music on. Maybe I just need some more grommets or something.]