NVVPSSPD

[ivan H]

New Vintage Valve Powered Stereo System Purchase Day.
I believe I've previously mentioned here on TTR that (some two plus decades ago) I had owned a British made Leak "point one" Stereo 60 amplifier & Varislope preamplifier. Unfortunately they were stolen in a burglary. Since then, I have been lookin to replace it with a similar unit, with no luck. They very rarely come up for sale & the couple of times that they did, the sellers were unwilling to ship to Australia. That all changed a few days ago when I found a Leak Stereo 60, Varislope Preamp/mixer & Trough Line FM Tuner offered for sale by a London, UK audio dealer. Shot them an email enquiring about the amplifier/pre-amp etc, asking for gutshot pics & whether they'd ship to Australia. Woke the next morning to an email with gutshot pics attached & confirmation that they would be happy to ship to Australia. During further communication they told me they would be mounting the amplifier (screwing it down) inside a wooden crate for shipping, clearly marking as "fragile" & "this way up" etc. Also that they would Air Freight & then courier it to me, as in their experience it's much kinder than regular shipping methods. They also offered to split the cost of this with me (how good is that). Payment was made last night. This is the actual stereo power amp purchased.

Varislope pre-amp.

Trough Line FM Tuner.

(Gutshot pics too large to upload).
These type items were made from approximately '62 through to '65.
So, a little general info about these. The Stereo 60 was the biggest amp made by Leak. Called a "point one" amplifier due to, at 25 watts (per side) output, they exhibit less than 0.1% THD (total harmonic distortion). Capable of 35 watts a side output at the onset of clipping (as with tube guitar amps, that's a solid 35 watts of useable power per side, so they can generate some VOLUME). The EL34's are running in Class AB1 push pull Ultralinear (screen grid taps at 25% rather than the common 50%). Matched output tubes are not needed & KT66's or 5881's can both be used with no problem, simply plug them in & good to go. The power amp features a (switchable) signal attenuator on the input, allowing it to be driven to full output either by a 125mV RMS signal (Varislope pre-amp), or a 1V RMS "line level" signal (external source).
Ok, onto this unit. The power amp has had the original, "prone to go leaky" TCC branded (paper in oil) coupling capacitors replaced with Ero MKT1813 capacitors, except the PI/power tube coupling capacitors, which are the Philips 341 "yellow box" types. I "may" at some time replace the coupling capacitors with Philips Mullard C296 "mustard" capacitors, or quality 600V paper in oil types. Being between 50 & 60 years old now, the original coupling capacitors needing to be changed out is pretty well standard practice. The filter/reservoir capacitors are still the original items so will be changed out pronto.
Likewise the pre-amp has a couple of coupling capacitors replaced, again with Philips 341's.
More pics to come when it arrives.
Then the next thing is to source some
decent speakers for it. Preferable would be 3 way horns, as a tube stereo through a good horn system can sound phenomenal, & LOUD (though a good horn system can be costly), or some nice, high efficiency 3 way speakers. I may hit up the tube audio forums for suggestions regarding choice of these. Cheers

 

[steveb63]

Way cool Ivan.

I'm a little jealous, that is badazz.

 

[jtcnj]

Sweet!
Best of luck with the shipping process.

Around 1990 I was into speaker building and was considering taking the plunge into tube audio amps.
Never did, and who knew I would get into guitar and tube amps 25 years later....

 

[syscokid]

Congrats and Happy Mullard Day...

 

[Thatbastarddon]

Congratulations sir!!! That’s fantastic!!!

 

[ivan H]

Thanks guys, I really am over the moon to finally get another of these. I had almost resigned myself to needing to get the transformers wound up (Majestic Transformer Co in the UK) & building myself as the only way of getting another one.

Sweet!
Best of luck with the shipping process.

Around 1990 I was into speaker building and was considering taking the plunge into tube audio amps.
Never did, and who knew I would get into guitar and tube amps 25 years later....

Thanks, hopefully all will go well. It does seem they are quite experienced in shipping items like this.
Building my own speakers does seem an attractive proposition, especially as I'd prefer horns. I've just started to research the subject. That said, woodworking isn't my forte, though I could farm that part out.
If you've not had the pleasure of hearing a good tube stereo through decent speakers, you're in for a real treat if & when you do.
If one can build tube guitar amps, they could build stereo amps just as well. If this sounds like something you'd be interested in, I recommend getting a hold of the book "Mullard Circuits for Audio Amplifiers". This (reprint) is available from several places quite cheaply, or can be downloaded.

Congrats and Happy Mullard Day...

Thanks, & yes, Mullard "shield logo" EL34's, though being staple plate types they are obviously replacements. The original EL34's would have been xf1's or xf2's. Still, can't complain about it having operable Mullard's.
Hopefully it clears our Aussie customs quickly. Cheers

 

[ivan H]

Firstly, I'm not sure I've posted this in the right forum, being that it's an audio amplifier rather than instrument amplifier. If so, perhaps a moderator could kindly move the thread to a more appropriate forum.

So, while the wooden shipping crate was being made to fit the power amplifier, staff had contacted me asking if I would prefer a Varislope 2 pre-amp/mixer rather than the Varislope 3, as the "2" pre-amp was the correct model for this amplifier, with the "3" pre-amp being intended for use with a couple of monoblocks. Of course, I agreed to this, especially as it was the same type pre-amp I had previously owned. It was this "correct to the amp" Varislope 2 unit that they had sent gutshots of. I also did not purchase the Trough Line 2 Tuner (even though it is an interesting item, there are better types if I had wanted a vintage valve driven tuner).
After paying import duties & taxes, then waiting for it to clear customs, it all arrived yesterday. I took a very extended lunch break to un-box it & have a look see.
And man, was it ever well packaged. Not double boxed, this thing was "quad" boxed, with a suitably thick layer of styrofoam sheet between each cardboard carton, several metres of packing tape sealing each carton & the whole thing then shrink wrapped. Getting it all unboxed was quite an effort. Opening the innermost 4th carton, I found bubble wrap, lots of bubble wrap, which finally revealed "another" cardboard carton containing (yes, more bubble wrap, &) the Varislope 2 pre-amp. This being quite sturdily constructed with an all enclosing steel chassis, did not really require the protection of being mounted into a wooden crate & survived the journey without a problem. A few pics of the pre-amp/mixer



And a gutshot of the circuitry

The Erie "tubular ceramic sheathed" carbon composite resistors, TCC "minipack" electrolytic capacitors, RS dogbones & RS Silver Mica capacitors are all original items. The original, "prone to go leaky with age" TCC "metalpak" paper in oil coupling capacitors have been replaced by the small, darkish green Ero MKT1813 capacitors & the two "yellow block" Philips 341 capacitors. Not shown, but on the other side of the board are 4 x EF86 pentodes, two Mullard's & two Mazda's. I'll be ordering a matched quad of NOS/NIB 1961 dated Brimar EF86's for it (can't find 4 matched Mullard's).
After removing the carton containing the pre-amp, I found this "purpose built" wooden crate

Finger joined corners, hinged lid, again, stacks of bubble wrap, then the bubble wrapped valves. Then, after removing more styrofoam blocks I found the power amp screwed down to the base of the box. More to follow. Cheers

 

[SG John]

That is sick dude! I assume for vinyl only, correct. Hope you have some nice speakers for it.

Now, I should do something about all the H. H. Scott stuff someone recently gave me.

 

[67plexi]

Ivan I have a pair of EV 350T if you need them they need diaphragms

https://products.electrovoice.com/binary/T350%20EDS.pdf

 

[ivan H]

So, after prying the very tightly fitted styrofoam from the perimeter of the power amp, I was able to get at the screws mounting it into the crate.
And here it is as came out of the crate

All valve positions clearly marked so the valves (which are likewise numbered) can go back into their previous positions.

The two upright white ceramic items are dual 440r/440r wire wound power tube cathode resistors (so each power tube has its own 440r cathode resistor). The cylindrical item between these dual cathode resistors is the filter choke.

Typical early 60's British with the 3 prong Bulgin AC receptacle, Belling Lee fuse holder etc. The figure 8 two core flex exiting the rear of the power amp plugs into the back of the pre-amp to allow both units to be switched on.
The power transformer primary winding voltage tap selector & output transformer secondary winding impedance tap selectors can be seen on the transformer end bell tops, again typically early 60's British.

Above is the AC power cable (wall plug will need to be changed for our Aussie type) & the umbilical cable (with octal fittings) that connects the power & pre amps.
I didn't have time to take gutshot pics, will have to do this evening & post.
As can be seen, it's in need of a little exterior clean & shows some surface wear, but considering its between 57 & 59 years old & still operating just fine, it's not too bad.
I'll be running it through a pair of Klipsch Heresey speakers. I'd really like some Klipsch La Scala's or Klipschorns, but have you seen the price of these things. Maybe in the future I'll have a crack at making a pair of La Scala clones, but first things first, I'll be replacing the filter/reservoir capacitors in both the power & pre-amp (the main filter's relief seal is just starting to rupture), and the electrolytic bypass capacitors in both units. Also will be checking all those Erie carbon comp resistors for drift & considering some higher (audio) quality coupling capacitors.
Power amp gutshots to come. Cheers

 

[CoyotesGator]

Absolutely gorgeous!

I have had a pair of La Scala's since the mid 1980's. I have never thought of replacing them with something else.

They really come alive with volume and the bigger the room the better.

 

[ivan H]

That is sick dude! I assume for vinyl only, correct. Hope you have some nice speakers for it.

Now, I should do something about all the H. H. Scott stuff someone recently gave me.

Thanks, & yes, I'll be using for vinyls, though my buddy that I share the house with will probably be running his tape deck through it too, as he has a LOT of cassette tapes.
Speakers are Klipsch Heresy's that have had the crossovers upgraded with Sonicaps.



The "close listening" tilt back risers are not original Klipsch items, but are made to the correct dimensions

And the grill cloths.

I'll refinish the enclosures sometime down the track. I did look at several speakers types, Altec's, JBL's, EV's, Altec Lansing etc. The purchase of the first pair of Heresy's I tried for fell through, then I got beat to a pair of Altec model 4's, then a pair of Klipsch Cornwalls, eventually got these.

Yes, you should do something with the Scott gear.

Ivan I have a pair of EV 350T if you need them they need diaphragms

https://products.electrovoice.com/binary/T350%20EDS.pdf

View attachment 86173

Thanks for the offer, appreciated.

I have had a pair of La Scala's since the mid 1980's. I have never thought of replacing them with something else.

They really come alive with volume and the bigger the room the better.

Awesome. Anyone who has not experienced a decent audio amp through a good, efficient horn speaker system really doesn't know what they are missing out on.

That's one of the good things about living in Oz,,, plenty of wide open space when one feels like getting LOUD.
Seeing as I've got a couple more pic, I best post again. Cheers

 

[ivan H]

Power amp gutshots

As can be seen, the relief seal has ruptured on the 1st main filter capacitor (lower dual cap can) while the relief seal is bulged on the 2nd filter capacitor (upper dual cap can). Being nearly 60 years old, this is to be expected. They will be replaced with Richey Gold's that I'm conditioning at the moment (current limiting). If possible, I'll gut the original cans & fit the new cans inside them to preserve the look of the amp.
The amp utilises a C/L/C (capacitor/inductor/capacitor) network for the main filter. All other filter caps & electrolytic cathode bypass capacitors in the power & pre amps will also be replaced.

Whoever previously replaced the coupling caps was messy with the resin spatter, though it's not really showing in the pic. I'll clean as best I can.
As expected, the old Erie type 9 resistors are all reading high & out of spec (680k's reading near 740k, 3m3's reading near 4meg etc, etc), so though the amp is operational, it wouldn't be operating at all optimally. All resistors will be replaced with 1 watt, 500V rated carbon films, as will those in the pre-amp. Resistors in the HT string will be replaced with metal oxide's.
As the original coupling caps were aluminium foil/paper in oil types, I figure I may as well replace the Ero MKT 1813's & Philips 341's with these type while I'm in there.
For anyone interested, I'll include the schematics & layouts.



Cheers

 

[ninjaking67]

Wow! That is some very cool gear!

 

[ibmorjamn]

New Vintage Valve Powered Stereo System Purchase Day.
I believe I've previously mentioned here on TTR that (some two plus decades ago) I had owned a British made Leak "point one" Stereo 60 amplifier & Varislope preamplifier. Unfortunately they were stolen in a burglary. Since then, I have been lookin to replace it with a similar unit, with no luck. They very rarely come up for sale & the couple of times that they did, the sellers were unwilling to ship to Australia. That all changed a few days ago when I found a Leak Stereo 60, Varislope Preamp/mixer & Trough Line FM Tuner offered for sale by a London, UK audio dealer. Shot them an email enquiring about the amplifier/pre-amp etc, asking for gutshot pics & whether they'd ship to Australia. Woke the next morning to an email with gutshot pics attached & confirmation that they would be happy to ship to Australia. During further communication they told me they would be mounting the amplifier (screwing it down) inside a wooden crate for shipping, clearly marking as "fragile" & "this way up" etc. Also that they would Air Freight & then courier it to me, as in their experience it's much kinder than regular shipping methods. They also offered to split the cost of this with me (how good is that). Payment was made last night. This is the actual stereo power amp purchased.
View attachment 85736
Varislope pre-amp.
View attachment 85734
Trough Line FM Tuner.
View attachment 85735
(Gutshot pics too large to upload).
These type items were made from approximately '62 through to '65.
So, a little general info about these. The Stereo 60 was the biggest amp made by Leak. Called a "point one" amplifier due to, at 25 watts (per side) output, they exhibit less than 0.1% THD (total harmonic distortion). Capable of 35 watts a side output at the onset of clipping (as with tube guitar amps, that's a solid 35 watts of useable power per side, so they can generate some VOLUME). The EL34's are running in Class AB1 push pull Ultralinear (screen grid taps at 25% rather than the common 50%). Matched output tubes are not needed & KT66's or 5881's can both be used with no problem, simply plug them in & good to go. The power amp features a (switchable) signal attenuator on the input, allowing it to be driven to full output either by a 125mV RMS signal (Varislope pre-amp), or a 1V RMS "line level" signal (external source).
Ok, onto this unit. The power amp has had the original, "prone to go leaky" TCC branded (paper in oil) coupling capacitors replaced with Ero MKT1813 capacitors, except the PI/power tube coupling capacitors, which are the Philips 341 "yellow box" types. I "may" at some time replace the coupling capacitors with Philips Mullard C296 "mustard" capacitors, or quality 600V paper in oil types. Being between 50 & 60 years old now, the original coupling capacitors needing to be changed out is pretty well standard practice. The filter/reservoir capacitors are still the original items so will be changed out pronto.
Likewise the pre-amp has a couple of coupling capacitors replaced, again with Philips 341's.
More pics to come when it arrives.
Then the next thing is to source some
decent speakers for it. Preferable would be 3 way horns, as a tube stereo through a good horn system can sound phenomenal, & LOUD (though a good horn system can be costly), or some nice, high efficiency 3 way speakers. I may hit up the tube audio forums for suggestions regarding choice of these. Cheers

All I can say is wow. That gear makes everything else just pale in comparison.
Thanks for posting the thread. I had no idea that stuff even existed.
I do have a old Pioneer console that uses those odd tube style pin connectors but it needs work.

 

[ivan H]

Thanks guys. So over a few weekend evenings I replaced the filter/reservoir capacitors, cathode bypass capacitors then replaced all the old, out of spec Erie (type 9) carbon comp resistors with carbon film's. I also replaced the Ero MKT1813 capacitors with K40Y-9 paper in oil types.

I'll replace the Philips 341 yellow block type output coupling capacitors with K40Y-9's too when they arrive. First power up was done with current production valves installed, rather than the Mullard's that it came with. With the voltage checks done it was time to run a signal through it. For this I used my buddies old cassette tape deck through the Varislope pre-amp. This is when, while at considerable volume, an intermittent fault showed up in the left channel (pops & occasional short drop in volume).
Unsure of whether it was coming from the pre-amp or power amp, I ran a CD player straight into the power amp's RCA inputs. Turned out the problem was in the power amp & was tracked down to be the left channel phase inverter's valve socket. The original sockets are the old British McMurdo types that feature "split wafer" contact pins & the non inverting triode's cathode pin had one half of the contact pin broken off, so when at volume (which was pretty much vibrating the whole house), the socket pin was intermittently loosing contact with the valve pin. I had given all sockets a shot of contact cleaner & inserted/wriggled valves into them, but hadn't inspected closely enough to pick up the damaged pin. After ordering an "under chassis" mounting socket & replacing it the amp is 100% & running fine. Next is the Varislope pre-amp, as again a lot of those Erie resistors (those that can be accurately measured in circuit) are reading high. Cheers