Hello, I know this subject has been done to death and I am reading through the old posts - and https://andydoz.blogspot.com/2019/09/the-comprehensive-linn-valhalla-repair.html
Let me tell you my situation. I purchased a perfectly working un modified valhalla.. i tested it, all good, but I knew it was a bit dated. It worked and I checked all the HV and low V. All good ( 300+v on caps ) motor span no probs. Caps looked old.
My plan was to replace things one at a time, starting with R1, testing at every stage to ensure it still worked.
I know this post will offend some people as I am looking for a hand for something thats been done a 1000 times
I first changed R1 to a inrush varistor - I made the mistake of not do ing this one thing and re checking, as was my plan. One thing replace, check next thing.
At the same time as R1 I also changed R2 & R3 with 7w 15k wire wounds as I thought "why not - easy "
Well after the 2 changes the valhalla no longer works. I get no 300+v DC on caps on C1, and basically a dead board.
I have traced the HV with my meeter the varister seems OK, fuse OK. I think I maybe burnt a copper track with the big resistors.
Can anyone give me a hand fixing this? I have a scope ( that I know how to use ) a mulimeter and I probably even have a isolation transformer somewhare .
My goal is to have a valhalla in an external box I can use between decks & do a real comparison butween a basic supply ( .2uf 90deg cap based phase shift ) and a DIY geddon so see if a moron like me could actually hear a difference.
If anyone is up for helping I would be greatful.
Thanks
Chris
Let me tell you my situation. I purchased a perfectly working un modified valhalla.. i tested it, all good, but I knew it was a bit dated. It worked and I checked all the HV and low V. All good ( 300+v on caps ) motor span no probs. Caps looked old.
My plan was to replace things one at a time, starting with R1, testing at every stage to ensure it still worked.
I know this post will offend some people as I am looking for a hand for something thats been done a 1000 times
I first changed R1 to a inrush varistor - I made the mistake of not do ing this one thing and re checking, as was my plan. One thing replace, check next thing.
At the same time as R1 I also changed R2 & R3 with 7w 15k wire wounds as I thought "why not - easy "
Well after the 2 changes the valhalla no longer works. I get no 300+v DC on caps on C1, and basically a dead board.
I have traced the HV with my meeter the varister seems OK, fuse OK. I think I maybe burnt a copper track with the big resistors.
Can anyone give me a hand fixing this? I have a scope ( that I know how to use ) a mulimeter and I probably even have a isolation transformer somewhare .
My goal is to have a valhalla in an external box I can use between decks & do a real comparison butween a basic supply ( .2uf 90deg cap based phase shift ) and a DIY geddon so see if a moron like me could actually hear a difference.
If anyone is up for helping I would be greatful.
Thanks
Chris
Also test each component prior to using it.
Bear in mind that working with the AC line voltage (and any voltage over 50V) is dangerous,
and requires special techniques and equipment. Do not do so unless you have the proper experience
and test gear. You must use an AC line isolation transformer, for example.
Bear in mind that working with the AC line voltage (and any voltage over 50V) is dangerous,
and requires special techniques and equipment. Do not do so unless you have the proper experience
and test gear. You must use an AC line isolation transformer, for example.
Modding a Valhalla is beyond my capabilities, but I did use a stock Valhalla mounted in an external enclosure for a while. I thought there was a subtle improvement, but who knows? I ended up buying a Hercules II, as it has the same footprint, and has 45 RPM. It was definitely an improvement over the stock Valhalla. I'm still enjoying it. 🙂
jeff
You say you think you burnt a track - well that is just a visual inspection and continuity test. Bridge with a piece of copper wire if found wanting.
Don't remove components needlessly.
If you've damaged a track fitting new components you'll only damage further by again removing them and refitting the originals.
If you must remove old components and don't need to reuse, cut the leads then unsolder each wire stub. Components can usually be replaced, PCB less easily replaced.
Don't remove components needlessly.
If you've damaged a track fitting new components you'll only damage further by again removing them and refitting the originals.
If you must remove old components and don't need to reuse, cut the leads then unsolder each wire stub. Components can usually be replaced, PCB less easily replaced.
Hi Chris, did you ever get this resolved. I repair Valhallas as well as Axis boards and do a fair few per month. If you are still stuck I might be able to give you a few pointers.