a-1

Hello good people of Audiokarma! Since this is my 1st original post here, here's a couple of words about myself. I am from Canada and just like most, if not all of you I enjoy good music, good sound and some DIY-ing during my non-existent spare time. I've been a quiet observer of Audiokarma for...

Title verbatim, when I touch the volume knob on this I get a buzzing noise through my speakers. I noticed this when I first got the unit and now that I've done some work on it and fired it up again, was reminded the issue's still there. (The A-1 in particular has a weird pot where the balance...

My nearly perfectly restored Yamaha A-1 still randomly cuts out! Power stays on and no fuse blown or magic smoke and amp runs relatively cool. All caps have been replaced. Brand new Omron speaker relay replaced. Offset, idling, all very stable and correct from the service manual. Most of the...

Hello all. The Yamaha A-1 has an aesthetically beautiful stereo volume knob. But, the flat disc section that controls the …. channel has worn lose in the centre. What’s the best cure? Blob of glue? Some substance to ‘pack’ the interior so that it’s a tighter fit? (Both of the above seem like...

Hi, I have a Yamaha A-1 that I’ve been working on and is now sounding great and has stable readings for Drive Circuit DC Offset, Idling Current, Power Supply voltage as per the manual. But, powering off just now by pressing the power button on the amp led to a substantial thump through the...

Can anyone tell me how, or direct me to a page, that explains how to test a dual jfet? I want to test the 2SK100’s I have in my Yamaha C4 and A1 with a DMM. Apparently, if they’re working well, they’re interchangeable. However, I have issues in one channel in each amp and confirming their...

I got this and a couple other A-1's to restore and decided to start on the JDM version as its not as common here in the USA. Powered up with a Step Down transformer . Power switches latching is intermittent and needs to be addressed , I have done this before and have a video on youtube...

Need to replace some 1.5Kohm resistors in the Drive board of a DC coupled Yamaha A1 amp. Originals were carbon, anything inherently wrong or risky in using good quality metal film resistors which I have in stock?

Need to replace a pair of OT’s on a Yamaha A-1. Have a couple of recommendations but can anyone say which transistor pair is best suited OR has worked well in this particular amp (or both, of course!) Would like to place an order today if possible, so all replies much appreciated. Existing...

Need to replace some resistors on aYamaha A-1 amp. The Service Manual simply says they’re “Carbon 330ohms” but when ordering additional specs are offered such as: -power rating? -resistance tolerance? -voltage rating? Can anyone advise what I should be seeking for each of the above. (And how...

Please could anyone direct me to the simplest and most economical way of using a dummy load to set the adjustments of bias and offset on an integrated amplifier? The service manual just say connect a "dummy load resistance (70W) to the speaker terminals." Searched but just can't find any visuals...

There is a a 68 ohms 60mA fuse resistor found in the Yamaha A-1 and other Yamaha amps of the same period. Could anyone tell me what is the best substitute?

Hi guys, managed to score a Yammie A-1 stereo amplifier for the not so hefty sum of 110,- dollars. It was a bit of a gamble, the seller didn't have any information regarding the state of the amp nor did he post any photo's. His asking price was very reasonable so i made the jump. When it got...