N3w_Typ3 0 Report post Posted December 27, 2003 .. nice collection .. that a true D.I.Y people .. haha ... man i really respect you. I hope to see it and also test it during the meet ... heehee! Share this post Link to post Share on other sites
garc 0 Report post Posted December 29, 2003 May I know if the A47 variant final version in mint tin and Cmoy variant final version in mint tin is for sale? I would like know the price as well. Share this post Link to post Share on other sites
tropicalrips 0 Report post Posted December 29, 2003 the A47 variant will be for sale , i'm working on a volume control version, but its may not be in a mint tin , cause my volume pots are too big. price should be below $100, i'm going to try stacking the buffer op-amp to see if it improves the sound Share this post Link to post Share on other sites
garc 0 Report post Posted December 29, 2003 Looking forward to it Share this post Link to post Share on other sites
Tenson 0 Report post Posted December 29, 2003 So, which do you think sounds best out of them all? Share this post Link to post Share on other sites
tropicalrips 0 Report post Posted December 29, 2003 the cmoy variant sounds best to me completed the A47 variant with volume pot but i think my gain is too high, don't hav the full volume spectrum of the pot, is like very soft then normal level & full blast only first half of the pot has any effect on the volume, the 2nd half is full volume all the way the case is a Hammond , but i got the wrong one , its actually too small, can't fit a 9v batt i decided to use it anyway cause the aluminium one is on its way i use 2 A23 batts to power this amp, its running at 12v the pot is a copy of the Panasonic, the whole amps is really tight, ran out of space every way i turn, had to put the on/off switch on the side. but i must say it looks really sweet can see the A23 batt from here, the case is actually ment for 2 AA batt, but thats not enough to power the amp without a boost circuit (still working on that) don't know how long the A23 can last... i don't think i will try this amp in this case anymore, just too tight getting the same Hammond plastic case that can fit a 9v, its the same size but higher Share this post Link to post Share on other sites
augustineRS 0 Report post Posted December 30, 2003 You think it can fit an Altoids? I can supply the tins, got a bunch of them now(tasty). Most importantly, how does it go with low imp cans? Share this post Link to post Share on other sites
tropicalrips 0 Report post Posted December 30, 2003 in Altoids mint tin shoulb be no problem , but the volume pot will hav to be at the side want to trade your altoids tins i'm lazy to go find them its an improvement on low imp cans , better then a Cmoy, but the hiss is still there, sounds like a tape player with 32ohm headphones its a big improvement over the cmoy. CMK tried it today with his PX200, maybe he can giv a first impression on the amp, he's also the first person other then myself to hav heard the amp Share this post Link to post Share on other sites
tropicalrips 0 Report post Posted December 30, 2003 A47 variant porn Share this post Link to post Share on other sites
tropicalrips 0 Report post Posted December 30, 2003 (edited) 4 * 16v 470uF power caps & 1uF signal coupling caps with 2 NJM4556 op-amps it has the same layout as the A47 monster reduced the gain to 5.5 , but still can't get a bigger sweep with the volume pot anyone hav ideas how to solve this problem? could be pot itself causing this, but can't get higher quality volume pots Edited December 31, 2003 by tropicalrips Share this post Link to post Share on other sites
Q00 0 Report post Posted December 30, 2003 i think its the pot thats causing the problem.... Share this post Link to post Share on other sites
Firefox 0 Report post Posted December 31, 2003 You're using a linear pot. You need a log-pot for volume controls. Go to Larry Hi-fi to get the TKD 16mm pot if you have to. Be warned, it's $50 for the pot alone. The A47 was created for low gain, I don't see why you need high gain for portable head/ ear pieces. Low impedance drivers don't need high voltage. Even 2x gain is more than enough. Share this post Link to post Share on other sites
tropicalrips 0 Report post Posted December 31, 2003 i don't use low impedance headphones its a Koss porta-pro 60ohms this variant is not really an A47 anymore, its more like a 2 stage Cmoy, i just retain my original A47 layout Share this post Link to post Share on other sites
Firefox 0 Report post Posted December 31, 2003 i don't use low impedance headphones its a Koss porta-pro 60ohms this variant is not really an A47 anymore, its more like a 2 stage Cmoy, i just retain my original A47 layout That's still fairly low impedance. 2x gain is still enough if your portable throws out 1.6v RMS from the line-out. Share this post Link to post Share on other sites
cmk 0 Report post Posted December 31, 2003 CMK tried it today with his PX200, maybe he can giv a first impression on the amp, he's also the first person other then myself to hav heard the amp Both the Cmoy and its other brother can sure . Lots of gain - which is a thing. Will post more impressions once I've got my source sorted out. Share this post Link to post Share on other sites
