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inherited some stuff.. please enlighten me


MainFrame

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On 9/4/2017 at 12:15 PM, TubeHiFiNut said:

Glad to hear that the PAS3 worked and that you are getting it sorted out.

 

As has been previously stated, please do not poke around in the amps. This type of amp has LETHAL voltages. Touching the wrong thing can really ruin your day - forever.

 

@NOS Valves is correct: Get the amp into the hands of a qualified tech who is used to the protocols required to safely work on amps that use big transmitter tubes.

 

The reward for doing this the right way will be an amp that should satisfy your audio needs for many years to come - especially with efficient speakers like Klipsch.

 

I have 845 based amps and am amazed at how good they sound.

 

Good luck.



I really don't see what the safety concern is when A:  I'm obviously not working on ANYTHING while it's plugged in, and B:  the capacitors have no charge in them (I tested all the caps in the amps and they had no charge, but would take a charge.. so they're still functional to some point, but I'm planning on replacing them regardless before putting any power to the amps.  After testing out the PAS3 I discharged the caps before fixing the loose connection I found and cleaning the volume dial more thoroughly).  As I said, I have a background in electronics.. if there's no charge in the amp it is virtually impossible to get injured poking around in it (aside from the occasional cut on sharp metal and/or soldering iron burn, but I already have plenty of those.. non-lethal).  I've been around enough electricity to know to follow safety procedures.. I wouldn't exactly say installing a new breaker box in a 50 year old house is non-lethal.  Sure, it's not a lot of volts, but I assure you two 120V legs running in from a meter with 200 amp service is certainly enough to kill you.. and the fun part is, you can't shut it off.  I've worked on plenty of home appliances with high voltage, and not once have I had a problem after properly discharging the capacitors.  ¯\_(ツ)_/¯

I would love to have the luxury to just hand them off to someone and say fix these up and call me when you're done.. problem is, I can't afford to pay someone over $1k to look at them, so unless I'm shipping them out of town paying a "tech" go through them is out of the question (and I doubt you're offering to pay the bench fees for me).  My other options would be to sell them, or trash them.  As much as it seems like some people on here think I should get rid of the amps rather than take the time to get them all checked out and fixed up myself.. I'm not willing to do that.  This was one of my father in law's passions, and I'm not just going to throw them away.

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@MainFrame - Your call. Everything might be all nice and discharged now but the minute you power things up, that is no longer the case.

 

Just urging caution when you are not used to playing with 1000+ volt (at decent amperage) B+ supplies like my 845 amps run.

 

Best of luck with your amps - sounds like they could be pretty special.

 

I'm out. B)

 

 

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15 hours ago, TubeHiFiNut said:

@MainFrame - Your call. Everything might be all nice and discharged now but the minute you power things up, that is no longer the case.

 

Just urging caution when you are not used to playing with 1000+ volt (at decent amperage) B+ supplies like my 845 amps run.

 

Best of luck with your amps - sounds like they could be pretty special.

 

I'm out. B)

 

 



Definitely.. I'm sure there are plenty of people who don't understand how capacitors work (when I was repairing the HVAC system in my house earlier this summer I went in to a supply store to buy a replacement main run capacitor for the A/C compressor and the lady told me that people come in all the time carrying fully charged caps in their pockets :blink:).  1250V is a lot of juice, so I'll be sure to be cautious.  Any time I put power to a capacitor then need to work on the unit later I fully discharge everything with a resistor I wired up specifically for that purpose.. then double check each one with my DMM before touching anything else.  I also inspect everything for possible shorts and burnt out components prior to hitting it with any power.

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On 9/17/2017 at 4:58 PM, Dr Morbius said:

Just to let you know, I had NOS Valves redo my 4 different HH Scott tube amps over a 5 year period and they sound fabulous!!!  $125 each is really not a lot of money for heaven!  Also for goodness sakes drop the bose and get a pair of Klipsch for those amps, you will not be sorry.



I might go ahead and hit him up to run through the big amp.. I'm trying to get in touch with the dwilawyer guy to test the 811 output tubes but he hasn't responded yet.



I asked a sound engineer friend of mine about getting someone local to test everything for me.  He referred me to a guy he has had restore some guitar tube amps that are worth close to $10k, but when I talked to that guy he was saying it'd run me about $1100 to have him go through all three of them.  He said all the caps have to be replaced regardless due to their age, and the Heathkits need to be converted back to push-pull because the transformers won't work right with the single ended setup (as well as testing all the tubes).  I don't want to fool with converting the Heathkits since I'm sure my father in law set them up like that for a reason.  Replacing the caps should be easy enough and I figured I would go ahead and do that even if they've barely been used and test out fine.

I'm definitely going to get some either Klipsch, or maybe some Tannoy speakers.. I'll have to see what all is still in storage because there should be a set of speakers to go with the rest of it.  The Bose are just being used on my TV temporarily until I can get around to fixing my Cambridge Soundworks 7.1 surround system.  They sound decent for watching TV, but their frequency response is pretty poor IMO.  I'm only planning on using the tube amps for music.. I'll keep the 7.1 system hooked to the TV for computer games and movies.




On a side note.. some of my wife's relatives came to visit a couple months back, and they brought with them three big boxes of vacuum tubes that my father in law had collected over the years.  I haven't opened them up yet, but I plan on sorting through them and selling many of the less desirable ones to pay for any repairs that need to be made on the amps.

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10 hours ago, MainFrame said:

On a side note.. some of my wife's relatives came to visit a couple months back, and they brought with them three big boxes of vacuum tubes that my father in law had collected over the years.  I haven't opened them up yet, but I plan on sorting through them and selling many of the less desirable ones to pay for any repairs that need to be made on the amps.

An untested tube is nothing more than a 50yr old untested light bulb. I wouldn't buy one unless it was very rare and desirable, like a 45 I scored at an estate sale for $5. Check out Antique Electronic Supply www.tubesandmore.com where you'll see many tubes listed between 5 and 10 dollars each, and they've been tested before being listed for sale.

  I was watching American Restoration on TV today where a guy brought in a 60s record player and was told the tubes could be $50 each if they were bad. So much mis-information gets told to folks these days about tubes.

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19 hours ago, MainFrame said:



 the Heathkits need to be converted back to push-pull because the transformers won't work right with the single ended setup (as well as testing all the tubes).  I don't want to fool with converting the Heathkits since I'm sure my father in law set them up like that for a reason.  

 

It is possible to use push-pull opts single ended.  I would need to see a schematic of what your father in law did to determine if his method was valid.  If you have the time to reconstruct his modifications and post the schematic on here, I can look it over.

 

Maynard

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10 hours ago, Davecv41 said:

I was watching American Restoration on TV today where a guy brought in a 60s record player and was told the tubes could be $50 each if they were bad. So much mis-information gets told to folks these days about tubes.

I'm not an expert at tubes by any means, but to replace the tubes in my old Harman kardon receiver (need quad matched 7408), it would cost about $50 each.

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23 hours ago, Davecv41 said:

An untested tube is nothing more than a 50yr old untested light bulb. I wouldn't buy one unless it was very rare and desirable, like a 45 I scored at an estate sale for $5. Check out Antique Electronic Supply www.tubesandmore.com where you'll see many tubes listed between 5 and 10 dollars each, and they've been tested before being listed for sale.

  I was watching American Restoration on TV today where a guy brought in a 60s record player and was told the tubes could be $50 each if they were bad. So much mis-information gets told to folks these days about tubes.

 

 

I'm surprised that people even sell untested tubes.. who buys them?

 

Thanks for pointing me to the website, this will be a great resource for me.  I'm assuming their prices are mostly fair and accurate?  If so then I should have no problem funding any repairs needed for the amps, be able to buy a nice pair of speakers (if there's anything wrong with the ones that  should still be in storage), and have cash left over for a nice glass case for everything to go in.  I just took a quick look, and some of the tubes I have here are listed for over $300 a piece.. if the cheaper/less desirable ones can fetch about $10 each then I should have a couple thousand dollars worth of tubes to get rid of, assuming most of them test out good of course.

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Who sells untested tubes? Estate sales, garage sales, flippers on ePay who scored a bulk deal on a ham's estate, etc. Before the internet I went to an antique radio shop in San Diego for tubes and caps and stuff for a Philco 20 I was rebuilding, and they got the prices by looking it up in AES's catalog. That printed catalog likely set the market back then. Lately they've been about equal on prices with most mail order places I've seen. Good luck with the inheritance.

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