Thanks for the quick reply. That is what I was afraid of.
It was suggested elsewhere that I add a B1 buffer after the preamp. It doesn't look like that would be too expensive of a solution.
ACA kits sounded great after construction completed; but left on overnight one was cold and non-functional next day (LED still on, though); other was still OK. Where to start trouble-shooting?
-Thx
-Thx
Hi guys
Have a question around setting bias of this amp. Does it make any difference if we attach a load to the output? Someone told me I needed to but never read it here anywhere.....
4 Channels on my 420mm x 275mm heatsink runs way too hot, can't touch it!!! Just wanted to make sure my bias setting method was correct, no load and 10v on the Q1 drain.
Is it correct that these run at about 26 watts load or no load? So that means my setup would be around 100 watts at idle, hot.....
Thanks
Have a question around setting bias of this amp. Does it make any difference if we attach a load to the output? Someone told me I needed to but never read it here anywhere.....
4 Channels on my 420mm x 275mm heatsink runs way too hot, can't touch it!!! Just wanted to make sure my bias setting method was correct, no load and 10v on the Q1 drain.
Is it correct that these run at about 26 watts load or no load? So that means my setup would be around 100 watts at idle, hot.....
Thanks
Attachments
without Iq mod (one resistor 2K2) , Iq is app. 1.1A
that is around 21W of heat per channel
setting is just 10V in front of output cap
while setting - input grounded , load irrelevant
that is around 21W of heat per channel
setting is just 10V in front of output cap
while setting - input grounded , load irrelevant
Hi Nzlowie,
What rail are you using now? (I noticed you mentioning the desire to try 24V)
I really like the look of your case but I suspect the heatsink is not getting adequate
ventilation for cooling.
Dennis
What rail are you using now? (I noticed you mentioning the desire to try 24V)
I really like the look of your case but I suspect the heatsink is not getting adequate
ventilation for cooling.
Dennis
24 volts
Hi Everyone
I would like to try 24 volt supplies but I'm not sure if this will cause damage if I just plug the supplies in.
Thanks (and pardon my naivity!)
Chris
Hi Everyone
I would like to try 24 volt supplies but I'm not sure if this will cause damage if I just plug the supplies in.
Thanks (and pardon my naivity!)
Chris
24v
Hi
Once again my apologies- could you please point me in the right direction?
Thanks
Chris
Hi
Once again my apologies- could you please point me in the right direction?
Thanks
Chris
Hi Zen Mod
I bought the amp second hand so didn't build it.Therefore I'm not sure how to set the inner side of the output cap
Any help will be greatly appreciated.
Thanks
Chris
I bought the amp second hand so didn't build it.Therefore I'm not sure how to set the inner side of the output cap
Any help will be greatly appreciated.
Thanks
Chris
Chris,
You need the pictorial build guide. Here's a screen shot of the adjustment. Multimeter to Q1 and ground. Set the pot (blue plastic square with white screw adjustment) to 15v (or whatever your target is). Keep cover on as it will be when finished. With amp on, wait half hour and adjust again.
Attachments
How to replace of 2SK170 by J111
I have exhausted my 2SK170's I got from US and am actively looking for replacement JFET's. J111 as per these comments looks like a great candidate, got them super cheap from RSDelivers.in however it doesn't look like it's an apple to apple replacement for 2SK (.. tried replacing them in my working ACA channel..including considering the leads are different for J111), but did not work...guys, need some direction/headstart to make this possible.
I have exhausted my 2SK170's I got from US and am actively looking for replacement JFET's. J111 as per these comments looks like a great candidate, got them super cheap from RSDelivers.in however it doesn't look like it's an apple to apple replacement for 2SK (.. tried replacing them in my working ACA channel..including considering the leads are different for J111), but did not work...guys, need some direction/headstart to make this possible.
Thanks ZM
J309's are available and not too costly, there are 3 options ON Semi/NXP/Fairchild .... all smd [emoji31]