silverfishla
Headphoneus Supremus
Stupid question. Are the opamps in this unit singles or duals?
(I squeezed a heatsink on mine which is somewhat visible on the previous picture I posted).
linear supply I ordered from eBay
Are the opamps in this unit singles or duals?
577002B00000G. Any std package with 0.25" fin height or less should work. Might be able to pull off up to ~0.40" if mounted backward (pointed away from the 1/4 jack). I have a few in that range in my cart for whenever I pull the trigger on another digikey order. Even with the small heatsink I measure up to ~140F. Probably OK, but I'd prefer to have it run cooler.Got a part number for your heatsink?
Hey thanks a lot for answering my question. When I finally get the parts for my build, I think I'm going to stick a couple of Sparko's Labs singles in there if the specs match up.It uses two TI OPA551PAs (http://www.mouser.com/ProductDetail/Texas-Instruments/OPA551PA/?qs=wgAEGBTxy7kLauCnM%2btIHQ==). They are singles.
Interesting module. Datasheet mentions unity gain stability issues and output current isn't as high as the OPA551, so wonder if you'd run into issues with harder to drive HPs and higher volumes. I haven't tried rolling myself as the OPA551s seem to be great performers, but keep us up to date if you try it.Hey thanks a lot for answering my question. When I finally get the parts for my build, I think I'm going to stick a couple of Sparko's Labs singles in there if the specs match up.
Ha, I've done the same. Did sound good, but it may be because I'm coming back to a warm amp after a rough day at work. haha.Well, I accidentally left my NuHybrid on all day while I was at work and came home to listen to some music tonight. It sounds amazing having been on all day. I imagine that isn't the best idea, but the difference is noticeable!
Here it is, very happy so far.Can you send a link to the linear supply you bought?
Also, at the very bottom and top end the amp just starts crackling and hissing. If this is the behavior of a $40 pot I'd hate to see the original, but I think it is something else, maybe something I didn't do correctly? When not changing volume it sounds sublime. Anyone else have this behavior?
Pete, I am using the 2N3904 transistors, so probably the reason for the top/bottom noise is something else?For the input buffer transistors Q2 and Q3, did you use 2N3904 transistors? I saw some oscillation that produced noise like you described when I used FETs in those positions.
Pete
For the input buffer transistors Q2 and Q3, did you use 2N3904 transistors? I saw some oscillation that produced noise like you described when I used FETs in those positions.
Pete
Yes, I have this behavior too with the upgraded pot. Slight hissing and cracking at the bottom and top positions. Other than that it’s a great little amp and it’s currently my main amp.
Pete, I am using the 2N3904 transistors, so probably the reason for the top/bottom noise is something else?