HP 6115A Good Price?

[hifiguy99]

First time poster here. I have an opportunity to pick up two HP 6115A PS for about $300 USD locally.
Good condition, missing a few housing pieces here and there, some scratches and scuffs, but otherwise clean.
I don't need the second one either so I could resell that if need be.

I was just wondering if these PSs are good units to begin with since I will be working with audio amplifiers soon and a clean precision power supply would be quite helpful.

What do you guys think?

[Stray Electron]

   $300 for 2!   I can pick up good clean and COMPLETE precision PSs like that for about $40 on E-bay and for about $10 locally.  HP builds GOOD stuff but I would EXPECT to find bad caps in something that old.  Any of HP, Harrison or Lambda PSs should be more than adequate for what you're doing.  HP, Harrison and Lambda supplies usually don't bring much money on E-greed due to their weight and the high shipping costs. My advice is to look on E-bay for any in your area and bid low on them and then go pick them up in person to avoid the shipping costs.  I buy a lot of them from a local surplus outfit and I'm usually the only bidder and all of their auctions start at $9.95 so that usually all I pay for them.  Depending on the seller, 80% of the old HP, Harrison and Lambda supplies that I buy all work perfectly.

    Unless you NEED one of the Precision PSs, I would avoid them, they're more delicate and failure prone than the standard supplies and they're more complicated to repair and also require high precision parts. I think you'll be pleasantly surprised at the stability and accuracy of the standard HP and similar high quality supplies even the 30 and 40 year old ones.

   PS  FWIW  the HP 6115A came out in about 1972 so the ones that you're looking at have probably been around for a while.

[hifiguy99]

   $300 for 2!   I can pick up good clean and COMPLETE precision PSs like that for about $40 on E-bay and for about $10 locally.  HP builds GOOD stuff but I would EXPECT to find bad caps in something that old.  Any of HP, Harrison or Lambda PSs should be more than adequate for what you're doing.  HP, Harrison and Lambda supplies usually don't bring much money on E-greed due to their weight and the high shipping costs. My advice is to look on E-bay for any in your area and bid low on them and then go pick them up in person to avoid the shipping costs.  I buy a lot of them from a local surplus outfit and I'm usually the only bidder and all of their auctions start at $9.95 so that usually all I pay for them.  Depending on the seller, 80% of the old HP, Harrison and Lambda supplies that I buy all work perfectly.

    Unless you NEED one of the Precision PSs, I would avoid them, they're more delicate and failure prone than the standard supplies and they're more complicated to repair and also require high precision parts. I think you'll be pleasantly surprised at the stability and accuracy of the standard HP and similar high quality supplies even the 30 and 40 year old ones.

   PS  FWIW  the HP 6115A came out in about 1972 so the ones that you're looking at have probably been around for a while.

What do you suggest as a precision low ripple/noise PS then?
Everything on e-bay is overpriced. Live in the northern Illinois area and everything is overpriced around here. Now that you say it, that HP power supply is a bit overpriced, but I have seen people pay $100-$200 for a good unit.

[Old Printer]

Depending on your needs, I have picked up three of these under the BK Precision 1651 label on ebay and never paid more than $60 with shipping. The ITT tech school bankruptcy sale a few years ago put a ton of these on the market. The TEK unit is the same with a different color scheme as I was able to get the TEK service manual and schematics to fix one of them. The user manual is here:
https://www.tek.com/cps250-manual/cps250-user-manual

[Stray Electron]

What do you suggest as a precision low ripple/noise PS then?
Everything on e-bay is overpriced. Live in the northern Illinois area and everything is overpriced around here. Now that you say it, that HP power supply is a bit overpriced, but I have seen people pay $100-$200 for a good unit.

  Have you even looked at the prices for the HP 6115A  meter in the Completed auctions on E-bay?  One sold for $10, another for $100, another for LESS THAN $89 and another for LESS THAN $50.  The first three were all listed as "used" and "pre-owned" so should be fully functional per E-bay's rules.  Real world prices are far less than the two for $300 that you were quoted.

  Stop using the ridiculous asking prices prices in the for sale section of Ebay for any kind of accurate value. 

  "What do you suggest as a precision low ripple/noise PS then?"

   What kind of voltage and current range do you realistically need? And what ripple requirements?  For audio work, I suspect that most lab grade HP power supplies will work. 

   I just searched for "HP Power Supply" in the for sale section of E-bay and I got over 10 pages (probably MANY more) of hits with 200 hits per page so that's at least 2000 listings and that doesn't include the other GOOD brands like Harrison, Lambda, Precision Power Source, etc.

  "Everything on e-bay is overpriced. "

     Not everything, many sellers start their items at $9.95.  Try sorting the search results by cheapest first and ignore the clueless sellers with their ridiculously high asking prices.   You can also limit the results by the distance from your zip code if you intend to pick it up in person.

[GreyWoolfe]

Are you fixated on HP?  Old printer mentioned the ITT sell off.  I grabbed a GW-INSTEK GPC 3020 power supply.  It has about 1.2mV ripple.  Is that good enough for your purposes?  Here is a link for one at $60 USD with free shipping.  https://www.ebay.com/itm/GW-INSTEK-GPC-3020-Laboratory-DC-Power-Supply-Dual-Tracking-with-5V-3A-Fixed/253686109132?epid=1919387835&hash=item3b10ded3cc:g:77IAAOSw1m5bIEd3

[mtdoc]

The HP 6114a (0-40V) and 6115a (0-100V) are excellent precision PSUs that tend to age well. IF you need that precision and are on a tight budget (or are just into vintage test equipment) they are an excellent choice.

Check out this thread for some nice picks and discussion of what deals others have find on eBay.

And this thread for lots of great pics and discussion on an amazing restoration.

$300 for 2 in good condition is not bad but if money is tight you can do better on eBay with some patience. I have one 6114a and one 6115a. IIRC, I paid $80 for one and $100 for the other. Both were dead accurate on arrival and have proved dependable and stable since.

[mtdoc]

  I grabbed a GW-INSTEK GPC 3020 power supply.  It has about 1.2mV ripple.  Is that good enough for your purposes?  Here is a link for one at $60 USD with free shipping.

That’s a good price for a relatively high power, triple output supply. But I would not consider it low noise or low ripple as the OP specified.

Of course those terms are relative .... The OP needs to be more precise in defining his needs and budget.

[hifiguy99]

  Have you even looked at the prices for the HP 6115A  meter in the Completed auctions on E-bay?  One sold for $10, another for $100, another for LESS THAN $89 and another for LESS THAN $50.  The first three were all listed as "used" and "pre-owned" so should be fully functional per E-bay's rules.  Real world prices are far less than the two for $300 that you were quoted.

  Stop using the ridiculous asking prices prices in the for sale section of Ebay for any kind of accurate value. 

  "What do you suggest as a precision low ripple/noise PS then?"

   What kind of voltage and current range do you realistically need? And what ripple requirements?  For audio work, I suspect that most lab grade HP power supplies will work. 

   I just searched for "HP Power Supply" in the for sale section of E-bay and I got over 10 pages (probably MANY more) of hits with 200 hits per page so that's at least 2000 listings and that doesn't include the other GOOD brands like Harrison, Lambda, Precision Power Source, etc.

  "Everything on e-bay is overpriced. "

     Not everything, many sellers start their items at $9.95.  Try sorting the search results by cheapest first and ignore the clueless sellers with their ridiculously high asking prices.   You can also limit the results by the distance from your zip code if you intend to pick it up in person.

The cheapest working HP 6114a/6115a on ebay are in the high 100's, so I figure I would just wait till a cheap listing pops up. But as mtdoc mentioned, these power supplies are worth a decent amount of money for their performance especially in good condition. The ones that have been sold on eBay are quite dirty, but nothing I couldn't handle in terms of cleaning and touching up. 

That’s a good price for a relatively high power, triple output supply. But I would not consider it low noise or low ripple as the OP specified.

Of course those terms are relative .... The OP needs to be more precise in defining his needs and budget.

I would say 100uV is preffered in terms of ripple, and atleast 20V. Anything less than 250uV should work fine and 500uV is pushing it in terms of what I want. I found some Precision Power Designs PS for this purpose, but again, they have really high asking prices so I would have to wait a bit for one to come up. And they're even older than the HPs so restoring a unit may prove to be a little difficult. Budget is around $350 but I am quite flexible. Although I won't overpay for something that isn't worth that much.

[Old Printer]

I have found ebay an excellent source for this type of equipment, but it takes time to get the good deals. You need to know what you are looking for and what it usually sells for. A good part of it is chance, there are times when no one is looking for what you are interested in and the item goes for the original minimum bid. Unless you see an item  as soon as it is listed, buy it now sales are not usually the best deals. Shipping is also something to get educated on. Some sellers just charge enough to cover their costs, and some add in unseen handling costs running the price up. All this comes down to is doing your homework and being patient, and a little luck that no one is looking for what you are at the time the auction closes.

[Ordinaryman1971]

I have two of those precision power supplies. They are really precise. Amazingly precise. There are better deals to be had, you can definitely buy one of those for about $50 in so-so condition, or you can of course buy a broken one you have to put some work in.
They are heavy, if you have them shipped it would add another $50 or so to it. The transformers inside are beefy.
Instek makes nice power supplies, get GDP-3303S, it's very easy to use and has three channels, look at the resolution. 0.000...
Going back to HP... there is a certain quality and coolness to it. Those are really nice power supplies. There is a reason they are called "precise".
You can really dial in the voltage you want.
And it's an HP... at the top of it's engineering. You open one of those and you gasp with amazement. They are just beautiful inside.
So, all depends on what you are looking for, is it ok with you to have analog dials.... do you want some digital readout, do you need more than one channel... maybe one of the E36XX series would be better choice, they are more compact and equally precise.. and a lot lighter.
There is so many possibilities, maybe look at the HP system power supplies and just move the binding posts to the front.... the world is your oyster.
Do you need a precise power supply at all... maybe you just need a bench power supply. Get one of the GPC-3020, they are so cheap you can't go wrong and they work. Two of those and you set.... but I'm telling you there is something about those HPs....