sc351cobra

Just wanted to update everyone. I was able to get my amp fixed, My old audio friend check everything and replaced both tube sockets. I have been listening to it for about a week now and it sounds great with my SRX MRK3 phones. Thanks for all the help

Just ask for both normal and pro when you order? Didn't realize that was a custom made amp

Kevin Thanks I saw a picture of them in JimL mod. I was able to get in touch with a fellow I had used for in the past to repair a Lumley tube amp made in UK. When I told him what the amp was doing his first thought was that it was a front end problem with the fets that he no longer could get. This did not instill me with a lot of confidence. I could have him replace the first before going further into the repair and replacement of all the caps. Or will he be to test them? Grawk I believe the blue hawaii amp is pro bias only. My SR-x MK3 headphones are normal. There quite old made in about 1978

Kevin Thanks for the information as I am having no luck finding anyone in my area willing or able to repair it I'll give it a try myself. Will I be able to get the value of the resistors from the color coding on them.

Just one more question are there any new tube amps that I can use my SR-X MK2 headphones with?

Thanks for the help guys but the amp has now gone out in the right channel and output level of the right drops off at the same time channel goes out. The amp yesterday worked fine for over 2 hours today maybe 3 minutes. So I'm searching for for someone to repair and recap it in my area. I'm going into this with a lot of dread unlike in my younger years when I was a active audiophile and knew people in the area who worked on tube amps that has past me by along with my age. But then today is my 75th birthday so I'm happy to have made it this far. Just a note for Spitzer strand as it may seem as soon as I turn the amp off everything clears right and both chanels work wile the caps drain. I do have a solid state SRM-1/MK2 that I am listening to right now but sure miss my tubes. Plaurids thanks for the information on bias think I would be able to do that with care but I'm pretty sure the amp needs more then bias adjustment. But if I am able to get it repaired I will be checking the bias myself.

Just wanted to add that with my home audio tube amps I would keep a eye on the bias and keep it adjusted with the exception of my Audio Research D115 I never had the nerve to do the bias adjustments on it for fear of electrocuting myself

plaurids Thanks for the information and it could well be a tube bias issue . It is a right channel problem I know that now after putting the bad tube back in. I then put the tube that was in when the distortion started and have been listening for about an hour and the distortion has not come back. I will read the information about bias and if I feel confident I can do it I will give do at least that much. Right now I'm just waiting for the distortion to come back although I am very much afraid it is intermittent .

Spitzer Thanks for the reply I would not know how to check the offset and balance. Is there a service manual I could download or purchase that would tell me how to do it. I am going to put the old tube that went out back in as I remember what socket it was in and see if it's the same channel that has the distortion. My thought on doing that is that it may be the amp that took out the tube and not just a tube going bad.

I am a old audiophile 75 years now. I had stopped listening to music for for a number of years . About 9 months ago I decided I would like to listen to some music. The only way I had to do this was with my computer. I purchased a pair of Audeze headphones a Schitt Valhalla 2amp and dac and signed up for Spotify. Enjoyed listening again but I remembered listening to my Stax SR-X Mrk 2 headphones . I was able to get a pair of them NOS and a used SRM-/MRK2 again enjoyed this even more then the Audeze Schitt. Saw a SRM-T1S on ebay and as I have alwas been a tube guy I purchased it. Used it for about 2 months and one of the tube died. Replaced both tubes and it worked fine for about a month and one channel developed sever distortion. If I turn the amp off while listening the distortion goes away untill the amp sopts playing . Any help as to what may be going bad would be greatly appreciated . Wish I had the skill to do the thing recommenced in these pages but I do not. The most I have ever done it assemble some Dyna kits back in my younger days. Thanks for reading my post