luvdunhill Posted February 13, 2009 Report Posted February 13, 2009 I don't like the idea of destroying a pretty good amp that's fully functional for purposes which just dont happen to include my own. Digitalmind never had any hum issues with it on his gear and its only the AMT that causes me trouble. If it were broken, or faulty I'd have much less issue. I also like the idea that by the time I'm finished with the F5 (whenever that turns out to be) it'll be something that I put together entierly myself. ah, ok well, if Spritzer's currency drops through the floor again and starts selling things off, talk to him about a certain pair of heat sinks he has
Duggeh Posted February 13, 2009 Author Report Posted February 13, 2009 Took the lid off the Aleph to have a proper peek for the first time. Of course, I've no idea whats really going on in there, but there is an asymmtry. The right RCA connector has a small resistor wired in line with one of the earth connections on the cable, the left RCA connect does not. Would this offer any kind of explanation for why one channel has hum?
luvdunhill Posted February 13, 2009 Report Posted February 13, 2009 Took the lid off the Aleph to have a proper peek for the first time. Of course, I've no idea whats really going on in there, but there is an asymmtry. The right RCA connector has a small resistor wired in line with one of the earth connections on the cable, the left RCA connect does not. Would this offer any kind of explanation for why one channel has hum? perhaps, assuming that there is no continuity from one RCA earth to the other RCA earth. If there is continuity, then that means the outputs share a ground and that single resistor serves as a ground breaker for both outputs.
spritzer Posted February 13, 2009 Report Posted February 13, 2009 ah, ok well, if Spritzer's currency drops through the floor again and starts selling things off, talk to him about a certain pair of heat sinks he has Hey!! It hasn't even recuperated from the last crash... :'(
Duggeh Posted February 13, 2009 Author Report Posted February 13, 2009 If by continuity you mean all the earths are connected then yes. There is a screw post at one end of the board which the psu capacitors are banked on, a large number of wires connect to it, running from the RCA inputs, the XLR inputs, both earth speaker terminals and both amp boards. Both of the XLR inputs have their own resistors, although they're different to the right RCA one.
luvdunhill Posted February 13, 2009 Report Posted February 13, 2009 If by continuity you mean all the earths are connected then yes. There is a screw post at one end of the board which the psu capacitors are banked on, a large number of wires connect to it, running from the RCA inputs, the XLR inputs, both earth speaker terminals and both amp boards. Both of the XLR inputs have their own resistors, although they're different to the right RCA one. right, so think of it this way. If there was indeed a resistor from each RCA to ground, they would in effect be paralleled with each other. So, a single resistor in this case is equivalent.
Duggeh Posted February 13, 2009 Author Report Posted February 13, 2009 Some more information while I'm wheedling. When the headphones are connected and the amp is on but theres no input to the amp theres just the very lowest level of noise. Nonintrusive. Connect the left RCA input alone and that replaces the left channel low level hum with the low level "nothing playing yet" noise from the source. Which at the minute is an ipod. Just as insignificantly quiet. Connect the right RCA input alone and theres a slight buzzy hum in the right channel replacing the unconnected noise (which seems to be going away as the amp heats up). This level I could readily deal with. Connect both, and thats when the intrusive hum pops up, and is slightly louder on the right. It's not actually intrusive BAD, but its enough to annoy me because I'm not a high volume listener. And therein lies my rub.
DigiPete Posted February 14, 2009 Report Posted February 14, 2009 i'd buy digipete's stratos. should be plenty of power, to finish the job of blowing your ears off. Yeah Duggeh, do what Reks said
Smeggy Posted February 14, 2009 Report Posted February 14, 2009 any hints on what the F5 parts cost as shown above for two channels?
luvdunhill Posted February 14, 2009 Report Posted February 14, 2009 any hints on what the F5 parts cost as shown above for two channels? ya mean other than the link I gave to tech-diy that sells kits? heh anyways, Peter's build is using some premo stuff.. ever what makes a resistor cost $15?
luvdunhill Posted February 14, 2009 Report Posted February 14, 2009 DOH! >me dumbass!< heh, just razzing you a bit. Anyways, the owner of that place is a nice guy. The boards pictures above can be bought at the links posted in my Spring Cleaning for sale thread. The designer and seller of those boards is the guy who built the amp that is posted above
Smeggy Posted February 14, 2009 Report Posted February 14, 2009 cool, razzing is expected when I'm being dim The kit price looks good, add 2 boards, 2 PSUs and 4 heatsinks right? I hace no idea how much the whole PSU things would cost, I imagine they're way more than the amp bits.
luvdunhill Posted February 14, 2009 Report Posted February 14, 2009 cool, razzing is expected when I'm being dim The kit price looks good, add 2 boards, 2 PSUs and 4 heatsinks right? I hace no idea how much the whole PSU things would cost, I imagine they're way more than the amp bits. well, I can help there. The PSU are very simple CRC supplies. Which means, you need capacitors and resistors. Minimum you could get by with $50 or so plus whatever Peter is charging for the PSU PCB (for stereo amp). You could easily point-to-point this, but I'm not sure I'd recommend that for a first project. Then you need 2 bridge rectifiers and things like jacks wire and what not. Say, another $50. Finally the transformer itself, so say another $100. Heat sinks and the casing materials might be around this same cost, who knows. Depends if you go with surplus heat sinks and how easily you might be able to fabricate a case.
Smeggy Posted February 14, 2009 Report Posted February 14, 2009 a basic case is no trouble, the thing I like about this amp is that it actually looks easy to build, unlike many others
luvdunhill Posted March 1, 2009 Report Posted March 1, 2009 Duggeh: diyAudio Forums - Modushop.biz heatsinked enclosure + F5 Amplifier (Nearly Complete) incl traffo - Page 1
Duggeh Posted March 1, 2009 Author Report Posted March 1, 2009 Argh because I only read and never post there I can't contact him via his email link. I guess I'll have to make a few token posts and wait for the mods to open me up.
luvdunhill Posted March 1, 2009 Report Posted March 1, 2009 Argh because I only read and never post there I can't contact him via his email link. I guess I'll have to make a few token posts and wait for the mods to open me up. Duggeh: shoot me your e-mail via PM and I'll forward it his way. This might be like me telling Steve who lives in Port Aransas, Texas about a good deal in El Paso, Texas.. who knows... edit: see here http://www.s11audio.com/
swt61 Posted March 2, 2009 Report Posted March 2, 2009 Cool case! Duggeh old bean I hope you end up building this amp. It'll be cool to consult each other on our first DIY projects. I've gathered most of what I need now. Got a line on some nice caps, then it's basically just a few resistors and waiting for everything to arrive. Smeggy are you jumpin' in?
Smeggy Posted March 2, 2009 Report Posted March 2, 2009 I'd like to Steve, I'm already in for a Pico Dac and probably a pair of FET boards so It's going to be pushing my finances a bit to commit to one of these as well. If I can find parts cheap enough, I'd love to.
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