|
Post by dc on Jan 16, 2007 1:18:53 GMT
Hi DC, It's the extra capacitance we're concerned with here and not the brand of the capacitor so much. Anything 105C rated of reasonable quality will do the job nicely thanks! i'll just go for the ones that are rated for the longest life =D
|
|
|
Post by dc on Jan 16, 2007 2:18:48 GMT
ooh, another question, would low impedance capacitors be of help here?
|
|
|
Post by daggerlee on Jan 17, 2007 0:06:08 GMT
Just dropped an IC socket inside, currently running two OPA627's on a browndog. Astonishingly enough, the DC offset has dropped to +- 0.1 mV on each channel. Have some AD843's which I'll be rolling in soon.
|
|
|
Post by daggerlee on Jan 17, 2007 0:13:22 GMT
Just dropped an IC socket inside, currently running two OPA627's on a browndog. Astonishingly enough, the DC offset has dropped to +- 0.1 mV on each channel. Have some AD843's which I'll be rolling in soon. Weird, just rolled in two AD843's on a browndog and I think it's oscillating - I get a hum on my headphones, I can still here music though...
|
|
rickcr42
Fully Modded
Rest in peace my good friend.
Posts: 4,514
|
Post by rickcr42 on Jan 17, 2007 0:15:37 GMT
The "anti" 627 and depending on taste close to the single best op-am out there.The other would be the OPA627 if that is to your taste with the AD825 in the same class but a mix of the two (slam and detail of the AD843,midrange bloom of the OPA627)
|
|
|
Post by PinkFloyd on Jan 17, 2007 0:16:53 GMT
Just dropped an IC socket inside, currently running two OPA627's on a browndog. Astonishingly enough, the DC offset has dropped to +- 0.1 mV on each channel. Have some AD843's which I'll be rolling in soon. Not astonishing at all the 627 are FETs with extremely low offset. Are you using the BP versions? (military / medical grade)
|
|
|
Post by PinkFloyd on Jan 17, 2007 0:23:22 GMT
Just dropped an IC socket inside, currently running two OPA627's on a browndog. Astonishingly enough, the DC offset has dropped to +- 0.1 mV on each channel. Have some AD843's which I'll be rolling in soon. Weird, just rolled in two AD843's on a browndog and I think it's oscillating - I get a hum on my headphones, I can still here music though... Did you solder the 843's onto the Bdog yourself? If so may be worth reflowing just to make sure there's no dry / intermittent joint. You've obviously fitted a dip 8 socket (8 joints) and now a single to dual adaptor (16 joints) so that's 24 joints you've created.... check them all. the first thing I would do is to roll the original 5532 into the dip socket and see if it still hums.... AD823 is best in this position
|
|
|
Post by daggerlee on Jan 17, 2007 0:24:31 GMT
Just dropped an IC socket inside, currently running two OPA627's on a browndog. Astonishingly enough, the DC offset has dropped to +- 0.1 mV on each channel. Have some AD843's which I'll be rolling in soon. Not astonishing at all the 627 are FETs with extremely low offset. Are you using the BP versions? (military / medical grade) No, I'm using the AP versions. You've rolled in AD843's successfully right? Anything I should watch out for? I just rolled in two of em on a BD and they seem to be oscillating (loud buzzing). I heard that they can lock up if the power is too low?
|
|
|
Post by daggerlee on Jan 17, 2007 0:25:48 GMT
Weird, just rolled in two AD843's on a browndog and I think it's oscillating - I get a hum on my headphones, I can still here music though... Did you solder the 843's onto the Bdog yourself? If so may be worth reflowing just to make sure there's no dry / intermittent joint. You've obviously fitted a dip 8 socket (8 joints) and now a single to dual adaptor (16 joints) so that's 24 joints you've created.... check them all. the first thingh I would do is to roll the original 5532 into the dip socket and see if it still hums.... AD823 is best in this position Well I soldered two IC8 sockets to the Browndog...so it's AD843's -> DIP8 socket -> Browndog -> DIP8 socket -> Canamp...not the best signal stream But I'm using the same BD with the OPA627's and they work fine, and I've made sure that they're in there nice and snug... So by deduction, the solder joints on the IC8 on the board, and the solder joints on the IC8s on the Browndog are all good...leaving the connection between the AD843 and Browndog in question, and I'm sort of stumped why they wouldn't be correct... Also, the chips aren't getting hot, and they do pass a signal through all the buzzing.
|
|
|
Post by PinkFloyd on Jan 17, 2007 0:32:47 GMT
Not astonishing at all the 627 are FETs with extremely low offset. Are you using the BP versions? (military / medical grade) No, I'm using the AP versions. You've rolled in AD843's successfully right? Anything I should watch out for? I just rolled in two of em on a BD and they seem to be oscillating (loud buzzing). I heard that they can lock up if the power is too low? Nope, I fitted AD "823" I've vast experience with the 843 in other amps (notably the WNA MKlll) but haven't yet tried it in the HEED. My guess is it wouldn't be the chip of choice in the Heed as it's V minimum is 10 volts.... the HEED is 9V. Try the dual AD-823 (as prescribed).... it works and sounds fckin' great. If I typed AD-843 instead of AD-823 in any of my posts whether here or on Head-Fi I apologise...... AD-823 it is.
|
|
|
Post by daggerlee on Jan 17, 2007 0:35:12 GMT
Did you solder the 843's onto the Bdog yourself? If so may be worth reflowing just to make sure there's no dry / intermittent joint. You've obviously fitted a dip 8 socket (8 joints) and now a single to dual adaptor (16 joints) so that's 24 joints you've created.... check them all. the first thingh I would do is to roll the original 5532 into the dip socket and see if it still hums.... AD823 is best in this position Well I soldered two IC8 sockets to the Browndog...so it's AD843's -> DIP8 socket -> Browndog -> DIP8 socket -> Canamp...not the best signal stream But I'm using the same BD with the OPA627's and they work fine, and I've made sure that they're in there nice and snug... So by deduction, the solder joints on the IC8 on the board, and the solder joints on the IC8s on the Browndog are all good...leaving the connection between the AD843 and Browndog in question, and I'm sort of stumped why they wouldn't be correct... Also, the chips aren't getting hot, and they do pass a signal through all the buzzing. Oh, I see - on the first page you listed them as AD843's which is I guess where I got confused. I'll try to get ahold of some AD823's then...
|
|
Nigel
Been here a while!
Watching over Gotham City keeping us safe
Posts: 2,064
|
Post by Nigel on Jan 21, 2007 21:42:40 GMT
What about the power supply for this amp? A simple 9v transformer? Surely there are some possibilities for improvements. What about a regulated power supply?
|
|
|
Post by PinkFloyd on Jan 22, 2007 0:08:22 GMT
What about the power supply for this amp? A simple 9v transformer? Surely there are some possibilities for improvements. What about a regulated power supply? Just wait till you listen to her Nigel and all thoughts of regulated power supplies and gold plated nipples will disappear to be replaced by tapping toes and a grin like a Cheshire cat......
|
|
Nigel
Been here a while!
Watching over Gotham City keeping us safe
Posts: 2,064
|
Post by Nigel on Jan 22, 2007 0:25:11 GMT
OK, Mike.
|
|
|
Post by PinkFloyd on Jan 22, 2007 0:35:16 GMT
|
|
Nigel
Been here a while!
Watching over Gotham City keeping us safe
Posts: 2,064
|
Post by Nigel on Jan 22, 2007 0:38:32 GMT
Did you ever consider replacing the captive mains lead? Is it soldered when it enters the amp or simply connected to a connector block?
|
|
|
Post by PinkFloyd on Jan 22, 2007 0:48:42 GMT
Now with NOS 10Watt Sprague Koolohm non inductive power resistors: A big improvement across the board with these guys in place, especially in the dynamics department. The slam, the start stops, the sheer "juice" factor have all benefited from their insertion. They look like sticks of dynamite and they sound dynamite! Truckloads better than the stock 5 watt "Royale" power resistors and they run a lot Kooler too. The Koolohms are not generally available being NOS but I've got a few matched pairs I'll be willing to let go to CanAmp owners for £8 a pair.... contact me for details.
|
|
rickcr42
Fully Modded
Rest in peace my good friend.
Posts: 4,514
|
Post by rickcr42 on Jan 22, 2007 0:55:54 GMT
You still need to report on what you think of "resistor rolling" the amp mike
|
|
|
Post by PinkFloyd on Jan 22, 2007 0:57:30 GMT
Did you ever consider replacing the captive mains lead? Is it soldered when it enters the amp or simply connected to a connector block? Soldered directly (hardwired) to the PCB. I haven't considered replacing it, no. To fit an IEC socket would mean a solder joint at the IEC, solder joint at the PCB then another connection when you plug your IEC plug in.... why the need for three joints when the one that's there already is doing a perfectly good job? Less is more.
|
|
|
Post by PinkFloyd on Jan 22, 2007 1:12:34 GMT
You still need to report on what you think of "resistor rolling" the amp mike I just did Rick, the Koolohms beat the pants off the Mills and riedon.... I'll follow up in the resistor thread shortly..... Mike.
|
|
|
Post by PinkFloyd on Jan 22, 2007 1:20:23 GMT
CanAmp is now on its way to Nigel for a second opinion on the SQ... I trust his ears and await his evaluation.
Mike.
|
|
Nigel
Been here a while!
Watching over Gotham City keeping us safe
Posts: 2,064
|
Post by Nigel on Jan 22, 2007 11:27:17 GMT
Then we can see how it stacks up against the Chiarra, designed by Jon Linsley Hood, hand built in Scotland by the Pink one.
|
|
|
Post by daggerlee on Jan 25, 2007 3:25:13 GMT
oh when will the upgrades end! I will keep an eye out for some of those resistors over here in the states. a cursory search has already turned up some Koolohms, but they're 25W and would probably be too big. I received some more opamps - AD823, AD8620, LM4562. So far my favorite is the LM4562 - the AD823 is too thin/harsh for my taste, the AD8620 is smoother/more full bodied, but the LM4562 seems to have the best combination of richness and detail...this is all under cursory observations, have not done any critical listening yet. Also does anybody remember what the two caps up front by the opamp are rated for? I'd like to replace those as well someday...
|
|
|
Post by dc on Jan 25, 2007 9:12:10 GMT
mike/pink floyd: a quick question on the size of the 35v 10,000uF snap in capacitors are they 25mm or 30mm? or would both fit?
oh and another quick question, could i replace the film caps with polycarb caps and then bypass them with polyprops?
was originally thinking of the red WIMA polyesters bypassed with polyprops like you did, but i can get polycarbs for not much more, is this possible/advantageous?
thanks so much
dc
|
|
|
Post by dc on Jan 26, 2007 4:35:22 GMT
|
|