Need advice regarding preamp

[anitab54]

My husband bought 1970's Klipsch La Scala speakers in 1995. We divorced in 2010 and the speakers lived unused, in my my basement for 10 years. I brought them up, had them checked out and they sound great. I have no amp. My friend found Bottlehead amps and a matching preamp near me and told me they would be perfect, so I bought them yesterday. The guy that sold them to me bought these from the person who built the kits. His original pieces (2 amps and preamp) -the preamp developed a hum, so instead of fixing, he bought another Bottlehead preamp. I bought the 2 amps, and the 2nd preamp, and he threw in the preamp with the hum, and suggested I get it fixed. I hope I did the right thing I am 66, and have no mechanical talent. How do I get it fixed? What should it cost? How can I tell which preamp I should keep? Should I keep or sell the 2nd preamp? Will I be able to sell the 2nd preamp? Also, I don't think there are enough (inputs? outputs? (whatever you call them) for turntable - do you have suggestions? I've attached some photos. Any an all suggestions welcome. Thank you. This is like buying a car when you've never driven one ....

 

[Doc B]

Wow that's some really vintage stuff! The two boxes in front in the first pic are preamps, our Foreplay preamp from the 90s. You are correct that the Foreplay preamp does not handle a turntable directly. For that you need a separate phono preamp that goes between the turntable and the Foreplay preamp. We sold a phono preamp called the Seduction back then. It has since been refined and is now called the Reduction.

The two boxes to the rear in the first pic are the amps, one per channel. Those are Paraglows, the same vintage as the preamps and a good match indeed for La Scalas.

To cut to the chase you are correct that you don't really need the second Foreplay, so you could sell it and just keep the gear that is working right.

If you would like to learn how to work on this stuff we would be happy to help. The first thing to do would be to get copies of the manuals (we sell them as PDF files, downloadable). You would also need to pick up an inexpensive digital multimeter at Harbor Freight or Home Depot, etc. Then we could talk you through checking them over.

If you would rather have us check them over we can do that too. We have a repair service with a fixed rate that you can order. We ship you boxes to pack them in and you send them to us. We go through them and send them back. Honestly if they are working OK this is not absolutely necessary. https://bottlehead.com/product/repair-service/


If you just need help hooking it all together to make sure it all plays music we can help with that too. Just let us know. You would need some speaker cables from the amps to the speakers, a set of RCA interconnect cables to go between the preamp and the amps, and some kind of source like a smartphone with a 1/8" headphone to RCA adapter cable, a laptop with that same adapter, a CD player with RCA interconnects, DVD player with RCA interconnects, or something similar. 

 

[Paul Birkeland]

For some reason, I can't see your photos (apparently Dan can, which is helpful).

You're going to have a hoot with some old Paraglows and those Klipsch speakers.  The repairs that roll through Bottlehead all hit my bench.  For an old Paraglow, I like to put in a very different power supply and a more substantial cathode bias resistor for the 2A3s to tame the heat that those amps generate a bit better.  This is a little bit beyond our flat rate repair service, but not by a whole lot.  (I believe $350 the pair plus shipping boxes to you, you shipping amps to us, and us shipping amps back to you).

I can also gut old Paraglows and repackage them into a pair of bigger 8x10 plates and bases.  In this configuration, I use an even large cathode bias resistor that runs really cool, and everything is super spread out on the inside.  It's somewhat over the top, but these old amps are pretty special! My pair of Paraglows is done up just like that.

 

[Paul Joppa]

The Speco output transformer suggests that these are Paramours, not Paraglows. Also the lack of a flux band on the power transformer. If the large black transformer in the middle has a label on its back side (right side from the first photo) that would confirm it.

 

[Doc B]

Apologies. Was thinking Paramours but I typed Paraglows.

 

[Karl5150]

Anita?
You expressed hope that you had made a sound (pun intended) decision. I can tell you that you surely have. These guys, and the Bottlehead gear, are the real deal. I have no skin in the game except for my enjoyment of three BH systems.
Whichever way you go in getting your system up and running I expect you will be very happy.
Enjoy!
Karl

 

[Paul Birkeland]

Paramours can be refreshed with our flat rate repair service.  (I still can't open the pictures for some reason)  During the refresh, I can also test all your tubes for you as well.

-PB

 

[Doc B]

I had to download the pics to open them.

 

[anitab54]

Hi - I'm sorry I took so long to get back to you all. I wanted to update you and ask more advice My friend Howard suggested I buy these, and after I bought them, we took these to Howard's stereo guy, Mike to look over. Mike put the working pre-amp into the light colored box which matched the color of the amps. He did not touch the pre-amp with them hum, and agreed that I should send it to you for repair. My question is this. I was wondering after you fix the one with the hum if it will work better than the one I planned to keep. I wondered if there is a package deal to send in the two together and you fix the one with the hum and check out the one I was going to keep, and whichever is the best one, that would go into the light box and I would keep it, and sell the other one.

My other question is if it makes sense to have you check out the 2 amps. We tested these on Howard's stereo and they seem to work fine. I'm just asking.

Please advise. Thanks.

 

[Paul Birkeland]

Whereabouts in the country are you? 

There was a common mod that was done to the Foreplay I and II that reduced hum in a fair number of systems.  I can dig up my old manual and make a little picture if you would like to see what that looks like, as that may need to be what's done to the humming preamp. 

Two Foreplay II preamps will fit in one repair box without much risk of damage, as they aren't all that heavy, nor are they all that tall.  The amps would have to come in separate boxes. 

-PB

 

[Paul Birkeland]

Before you pull the trigger on a flat rate repair, this is the modification that may be present in one of your Foreplays but not the other.

 

[anitab54]

I don't know how to read a schematic. Sorry, the photos were in the correct orientation when I uploaded them. Don't know why they rotated.This is the preamp that hums.

 

[Paul Birkeland]

How about this?

 

[Paul Joppa]

Anita, I think we may be talking at cross purposes - apologies if that's the case.

Most of our customers build these as kits, and are glad to fix things themselves with a little help from the forum, and save some money. But in your case, that's only possible if you have a technician or knowledgeable friend readily available, and it still means arranging the work and transportation etc. (The repair service is $125 plus shipping one way, and it's possible that the only thing needed to quiet the humming preamp is to connect two terminals.)

I gather that 1) you don't particularly want to fuss with these, and 2) you do want to know from an authoritative source that they are up to snuff. In that case, sending them in for evaluation seems reasonable to me.

 

[anitab54]

Paul, so all that this preamp needs is that one wire and the humming will stop? Is it currently a foreplay 1 or 2? Does that wire have a name? What else do I need to know? I've never fixed anything in my life, but maybe I can find someone to help me? Do I need a schematic? How much is the schematic? Thanks.

It’s not that I don’t want to personally fix them, I don’t know how. I don’t have tools. Etc.

 

[Paul Joppa]

Both preamps are Foreplay 2 - I can tell from the label on the power transformers.

In the most recent picture that Paul Birkeland (yes there are two Pauls) posted, near the top, he indicated in red the two terminals that should be connected. A green wire goes to the center terminal of that terminal strip (labeled 13) and the one to the left of it (terminal 14) is the other. A short wire between these terminals should be soldered at each end. Technically, this connects the signal ground to the chassis ground - you can see that terminal 13 is bolted to the chassis.

(Whoever does the soldering should be aware that the copper signal ground wire passing through terminal 14 has a really tough plastic coating. Just in case - this calls for 60/40 tin/lead electronic solder with rosin flux; find someone who knows what that means!)

Back in the day (it came out in 1998 if I recall correctly), many customers but not all had a hum problem that was resolved with this modification, and I see from the picture you posted most recently that yours does not have this connection. So there is a good chance that this will resolve the hum prroblem. There are of course many other things that could have caused the hum, so you can't be certain it will work until it is tried.

You do not need a schematic to do this.

I also see from you last photo that this preamp has the stepped attenuators,  fancy boutique audiophile capacitors (the large yellow cylinders), and the current sources (the four small circuit boards) - so this is a top-of-the-line version of the Foreplay 2.

 

[Paul Birkeland]

Yes, I think it's a smart idea to try soldering a wire between those two terminals.  That could save you all the repair costs.  You could use this kit for the soldering part:
https://www.amazon.com/ANBES-Soldering-Iron-Kit-Electronics/dp/B06XZ31W3M/ref=sr_1_2?dchild=1&keywords=soldering+tool+kit&qid=1591545429&sr=8-2

For the piece of wire, if you have a cat5 networking cable sitting around, you can cut it apart and use the wire out of that to connect the two terminals.  YouTube has plentiful soldering videos as well.

-PB

 

[anitab54]

I talked to Howard (who suggested I buy these). He wants me to send in to you. Thank you for all of your help. You guys are great!! I will put both preamps in one box that you send me. You will fix one and check out the 2nd one and fix the second one if needed. I will pay $125 now and the shipping if that is allowed, but if I owe more for the 2nd amp, of course I will pay you. Additionally, I'd like to have you check out the amps which I know are $125 each also. I will feel much better if you bless them and I will get a receipt or something that shows you looked at them. One day, I will try to be brave and build a kit. And thank you again so much for your patience with me.

 

[Paul Birkeland]

If you're sending all of that in, let's just do both Foreplays for one repair fee in one repair box. 

-PB

 

[Karl5150]

Anita,
Do all the bottleheads following this a favor and post a photo once they are up and running in your system.
Good luck and good sound.