buildafriend

Sound Model X404 - Recap, Ground Mod, Retube
« on: January 22, 2019, 05:07:17 PM »
Hi guys,

I have a Sound X404 here that seems to be working great other than a sometimes failing 2 prong power plug. Usually I say if it aint broke don't fix it but the person would like the caps replaced, tubes changed, and a grounded plug added so here go's. I think it's a pretty rare and underrated piece. It seems to handle both bass and guitar very well while coming across as clean and thick. It only breaks up a hair at loud volumes with a strat with regular american pick ups.

I don't see a schematic anywhere online, or recognize the power tube type. Unfortunately there is no label on the power tubes other than RCA. Does anyone recognize these or have a schemo for this amp?
« Last Edit: January 22, 2019, 05:55:11 PM by buildafriend »


buildafriend

Re: Sound Model X404 - Recap and Ground
« Reply #1 on: January 22, 2019, 05:16:21 PM »
Does anyone recognize this tube?

buildafriend

Re: Sound Model X404 - Recap, Ground Mod, Retube
« Reply #2 on: January 22, 2019, 05:19:32 PM »
another pic of unidentified tube


buildafriend

Re: Sound Model X404 - Recap, Ground Mod, Retube
« Reply #4 on: January 22, 2019, 11:31:20 PM »

scott2000

Re: Sound Model X404 - Recap, Ground Mod, Retube
« Reply #5 on: January 23, 2019, 09:23:10 AM »
There's a mention of the 7868 in another model here...

https://www.premierguitar.com/articles/Souping_up_a_Sound_X-305-R

and here

http://www.tdpri.com/threads/sound-electronics-corp-mineola-ny-model-600.410123/


So maybe a possibility at best???

Good luck!

buildafriend

Re: Sound Model X404 - Recap, Ground Mod, Retube
« Reply #6 on: January 23, 2019, 11:06:18 PM »
Thanks Scott! I’m going guess you’re right for now. Time will tell.

There are some cool sounding mods in that 1st article too

buildafriend

Re: Sound Model X404 - Recap, Ground Mod, Retube New
« Reply #7 on: February 07, 2019, 10:10:31 AM »
Tubes caps and grounded power plug came in. I installed them all and it sounds much better. I think only have to troubleshoot one bad section that doesn’t “Bass boost” the way it should.

A note to anyone changing these power tubes - the electro harmonix ones will stretch out the output power tube sockets. Once you put them in the old tubes don’t fit right unless you go in with a micro screwdriver and bend the inside of the sockets back. I’m not taking that path, it sounds great with the new tubes. Much brighter and a little louder. It breaks up a little more at loud volumes now. You can hear the tele switch positions much more clearly and there is no amp buzz even at high volumes. This amp is underrated.
« Last Edit: February 07, 2019, 09:24:47 PM by buildafriend »


 

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