Forte 1a

hooch2259 · 6th February 2013, 08:57 AM

Im just about to acquire two 1A amps, both working. however Im told that one of them has a transformer buzz. I won't pretend to be an expert on circuit design but i can solder and I read an earlier thread re a 4a that had the same problem which was solved by replaced some caps and bridge rectifiers. Any comments would be very welcome..

Zen Mod · 6th February 2013, 12:01 PM

get them , post pics and then we'll see what's happening

hooch2259 · 11th February 2013, 10:37 PM

I have tried both amps. The buzz on the transformer turns out to be very mild. I did check the bias - one side much higher than the other 80mv / 130mv, after adjusting both around the 130mv now ( awful biasing pots ) and heat not too bad, you can hold your hand on the heat sinks..

Sound great with Yamaha NS1000 s

, no grain or glare, powerful solid bass. Id like to link the inputs and Bi amp - any issues here ?

Zen Mod · 11th February 2013, 11:01 PM

no issues

regarding crappy pots - replace them

use multiturns , with adequate setting screw position

6th February 2013, 08:57 AM	#1
hooch2259 diyAudio Member Join Date: Feb 2013	Forte 1a Im just about to acquire two 1A amps, both working. however Im told that one of them has a transformer buzz. I won't pretend to be an expert on circuit design but i can solder and I read an earlier thread re a 4a that had the same problem which was solved by replaced some caps and bridge rectifiers. Any comments would be very welcome..

6th February 2013, 12:01 PM	#2
Zen Mod diyAudio Member Join Date: Jan 2003 Location: ancient Batsch , behind Iron Curtain	get them , post pics and then we'll see what's happening __________________ my Papa is smarter than your Nelson ! tnx to clean thread ; Cook Book ; PSM LS Cook Book ; Baby Diyaudio FORUM ; Mighty ZM's Bloggg;I'm dumb

11th February 2013, 10:37 PM	#3
hooch2259 diyAudio Member Join Date: Feb 2013	Forte 1a I have tried both amps. The buzz on the transformer turns out to be very mild. I did check the bias - one side much higher than the other 80mv / 130mv, after adjusting both around the 130mv now ( awful biasing pots ) and heat not too bad, you can hold your hand on the heat sinks.. Sound great with Yamaha NS1000 s , no grain or glare, powerful solid bass. Id like to link the inputs and Bi amp - any issues here ?

11th February 2013, 11:01 PM	#4
Zen Mod diyAudio Member Join Date: Jan 2003 Location: ancient Batsch , behind Iron Curtain	no issues regarding crappy pots - replace them use multiturns , with adequate setting screw position __________________ my Papa is smarter than your Nelson ! tnx to clean thread ; Cook Book ; PSM LS Cook Book ; Baby Diyaudio FORUM ; Mighty ZM's Bloggg;I'm dumb

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