Author Topic: Best Tubes for 200S  (Read 2642 times)

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Offline fatlizzard

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Best Tubes for 200S
« on: December 18, 2004, 10:44:34 pm »
I recently bought a 66 - 67 200S and all the tubes were destroyed in shipping, any suggestion on the best brand tubes to use in this amp, I do want to stay with KT88's , Should I use the same make for all tubes or are certain makes better for different tubes, how about replacing the rectifier tube with a SS rectifier? is any modification needed ar is there something that can plug into the socket?
Thanks!!!!!!!!!!!!!

Offline Soundmasterg

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Best Tubes for 200S
« Reply #1 on: December 20, 2004, 03:26:33 pm »
For a 200S, I would recommend to go with JJ KT88's. They sound very good and give vood power and last a long time.

For the rectifier tube, JJ makes a good GZ34, and the chinese one is good too. You could also use a Weber Copper Cap WZ34 rectifier, which is a solid state plug in replacement that emulates the sound and function of a tube rectifier. That is what I have done in my 200S and it works and sounds GREAT and its only $20 and will outlast me. Check them out at www.webervst.com.

For preamp tubes, any 12ax7 should work. JJ, EI, EH, and Sovtek make good ones. I recommend the JJ however because it will give a more powerful and cleaner sound than the others I mentioned which suits a bass amp better. For the driver tube, you'll need a 6AN8 most likely, and the best to get there would be a NOS tube from Antique Electronics Supply in Arizona. Their site is www.tubesandmore.com.

Also, if you haven't yet, it would be a good idea to replace the electrolytic caps in your amp with new ones.

Offline fatlizzard

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200s tubes
« Reply #2 on: December 20, 2004, 09:59:20 pm »
Thanks for the info,This amp was damaged in shipping,all tubes broken and transformers pulled out, I would like to get it working before doing the cap replacement, however I do want to use a SS rectifier,can I change the rectifier without replacing the caps?
I have a bid in on e-bay for a set of Valve Art KT88's, if I don't win them I will go for the JJ's as I've heard lots of good remarks about them
Thanks !!!!!!!!!!!!

Offline Soundmasterg

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Best Tubes for 200S
« Reply #3 on: December 20, 2004, 10:38:22 pm »
People just don't know how to ship or pack tube amps. They are heavy, especially the Sunn stuff.
You can probably get it working before replacing the caps. Just hook the transformers and leads back up to where they are supposed to go. Also, if the tube sockets were damaged, you should replace them as they will most likely start arcing if they are chipped or cracked in any way. I think they are riveted in too, so you would have to drill out the rivets, replace the sockets with new ones, and then re-rivet them in again. Of course that would involve unsoldering and resoldering all the connections to the sockets too. Make sure to draw up a layout of how it is now before you do that.
The best solid state rectifier to use would be the WZ34 Copper Cap from webervst. It will plug right into the socket and is only $20. I'm using one in my 200S because I upped the filter cap values in the first 2 stages for more bass and the tube GZ34 can't take the higher cap values. I went to 110uf and 100uf instead of the stock 30uf and 20uf or whatever it is in the first two stages. Made a VERY big difference in the bass response and the amp sounds a LOT better now for bass. If you do this, you'll have to use series connected, lower voltage caps and 220k 1w resistors in parallel to each cap. For the 110uf, use two 220uf 350v caps. It would also be beneficial to rearrange the choke and drill some holes to add some turret lugs or connectors of some sort. This way you get more room in the chassis to use all the series connected caps, and you can still keep the layout well arranged. I could send pics of what I did if you want? I also added a ground buss and some other stuff, but you could get the idea. You could also just get the exact replacement can cap from vibroworld and triode electronics and other places, but that isn't as good of a solution in a number of ways, probably costs more, and you don't have as good of bass response. If you were in the Portland, Oregon area, I could help you out.