Leak Stereo 20 valve amp

[jandl100]

I clicked the eBay Buy It Now button on this yesterday. I go to collect it this evening. :)

http://i262.photobucket.com/albums/ii114/jandl100/LeakStereo20.jpg

Said by many to be a rather fine amp.

[Marco]

Well done, Jerry!

It's a veritable, highly desirable, classic. Let's hope everything is working ok. Have you got some spare valves just in case?

We expect the usual full write-up and pictures in due course :)

Marco.

[jandl100]

It's alleged to be A1 - here's the eBay auction link http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=320282302375&ssPageName=STRK:MEWN:IT&ih=011

Spoke to the seller this morning - says he'll set it up for a demo for me.

"Clean and tidy Leak stereo 20 power amp. I am selling this amp on behalf of a friend who is both an electronics engineer and valve amp enthusiast. He has owned this unit for around 18 years and has gradually replaced components over that time but kept the circuit original. The capacitors have been replaced with modern polypropelenes and one power supply cap has been replaced and sprayed gold to match the other. Many of the resistors have been replaced with high grade Holcos. A mains switch and removeable MDF base have been fitted along with high quality modern gold plated phono sockets and speaker binding posts. The base is essential to keep fingers away from live parts underneath. The mains lead with original Bulgin plug is included. The paintwork is in very good condition. The the original AC output blanked off. The result is a nice tidy and largely original amp which is reliable and sounds great."

:)

[Marco]

Sounds (and looks) like a nice clean example. Given its desirable status you should have no problem moving it on, should you wish to, and make a profit.

Can I come round and listen to it then? :lol: :lolsign:

;)

Marco.

[Primalsea]

The Leak ST20 is a remarkably modern sounding amp, not soft at all. Its not my favourite amp in the world but thats really a matter of IMHO rather than anything else. If there are any original resistors you may want to de solder them and test them with a DMM as it is very common for them to drift out of spec. The only one you want to keep is the large green one. The leak has an excellent safety feature; if theres a major problem the resistor gets so hot it de solders itself from the board and drops off.

[greenhomeelectronics]

You got a good deal there. The Stereo 20 is, in my opinion, an all time classic that still punches well above it's weight. Looks like a nice example too. You are very lucky I did not see it first :-) Reckon you got a bargain there....
Dave

[jandl100]

I picked it up last night - it was playing as I entered the room. Strange system - little JPW speakers sitting on the floor :scratch: but the amp was performing well. The guy turned the volume up - and up - I think the speakers would have given up before the amp did!

The little beastie is still in my car - waiting for the rain to stop & I'll go and get it in.

I hadn't realised how small it is! - real cute. :) Weighty little mite, too, some nice transformers there, I think.

[Ali Tait]

From what I've read and been told,the output transformers on these are superb.I heard one quite a while ago that had had all the components replaced with modern equivalents,and from memory it sounded very good,not what I would have expected from vintage gear (in general).A nice amp.Good investment too,it will only go up in value.

[jandl100]

Blimey, but it sounds good! :)

Have just rolled a couple of Mullard ECC83 toobs into it - wow, this is fun!

I need another Mullard ecc83, though - the dang thing takes 3, and I only had a pair .... ;) Anyone?

[jandl100]

Here's the "Blog" write-up for the fun & games to-date ....

Went Monday evening to collect the amp in Bristol (about an hour's drive). The amp was playing as I entered the room - strange setup - Naim CDP, not sure what pre, the Leak and some small JPW speakers sitting on the floor! Kinda weird - I think that's the speakers' permanent position. Anyway, he turned the volume control up - and up! - no problem. I got the feeling the speakers would give up before the amp!

Got it home late in the evening, after a visit to the Bristol IKEA as I had the wife along. :) Not very good outside lights at my place so I left it in the car rather than risk an accident bringing it in in the dark. We brought the IKEA shelves in, though ;). Raining Tuesday morning so I left it in the car and finally set it up early afternoon.

Hey, the things really quite small and decidely cute! I hadn't realised and was expecting a big hunk of chassis ... here it is at home with a standard CD case for size comparison ....

http://i262.photobucket.com/albums/ii114/jandl100/LeakStereo202.jpg

Connected it all up, double checked the wiring, clicked the power switch ...... nada, nothing, zilch. :(:scratch: Sigh. Looked at the fuse at the rear of the chassis - fine. Changed the fuse in the mains plug, twice! Nada. Double sigh. :(:(
Phoned the seller up to see if he had any suggestions ... nope, just the usual sensible stuff I had tried already. He said he'd phone the engineer up who had restored it. After the call, I continued vaguely fiddling ... cable connections, valve seating .... etc ..... tweaked the fuse holder at the back of the amp .... BINGO, a flicker of life in the valves, which then died. After a bit of occasionally successful (flicker, die) twiddling I found that the fuse only made proper contact if it isn't fully seated in the holder cap. Easy once you know - and it's been fine ever since. Phew! :)

OK - now I can listen to the dang thing. Bloody hell, that's clear and lucid! - no vintage amp blurriness and soggy bass here.

The usual question with a power amp in my current system was the first to be addressed. To use the power amp straight from the DAX Decade (which has an on-board pre-ampsection) or to route this through my EAR 802 pre-amp? :confused: A few to & fro swaps and the unambiguous result (as is usually, but not always the case) - yup, the EAR pre stays. More power, bass depth, presence, focus & tonal colour than with the DAX Decade alone.

So here is the current electronics stack (except the CDT) ....

http://i262.photobucket.com/albums/ii114/jandl100/LeakDAXEAR.jpg

"This sounds mighty fine", I thought, and relaxed with some mixed musical selections for an hour or so. Hmmm ... getting a bit twitchy after a while, the solo piano is a bit vague, imaging is a bit 2D. Let's see .... there are 3 ECC83 valves - no-name stock ones. I've got a pair of NOS Mullards, I'll swap 'em out and see if there's an improvement. ZOUNDS, YES!!! A full blown, totally engrossing musical presentation at last. Suddenly the piano changes from being a curiously flat plane directly between the speakers to a quite nicely focussed piano, centre stage and a little set back. Cripes, but it really is amazing what good NOS toobs can do. I've now sourced a 3rd Mullard, should get it in a day or so - thanks, Mike!! :) - will be interesting to hear if that continues the improvement.

So, to end yesterday's saga and sum up .... a seriously impressive sounding power amp - regardless of its vintage origins. I'd happily put it up against any amp out there - I'm not saying it would beat them all (whatever that means) but it sure as hell wouldn't be embarassed, either. Clear, lucid powerful, detailed - with a real presence and pizzazz to the sound.

[Prince of Darkness]

If you think that's small you should see my Rogers Cadet!:lolsign:

[Primalsea]

I'm glad its a goer for you. I read somewhere that the transformers are a bit marginal for their purpose but I personally think they are fairly huge. Much larger than those on most modern EL84 amps.

For me the ST20 is a bit of a Fugly Munter but it somehow manages to have that charm that makes you not mind having on show in your room.

[jandl100]

Yep, this evening I've been playing Bruckner's 3rd symphony - things don't get much louder than that in acoustic music - no problems or loudness/dynamic limitations at all - Big Grin time, actually. Those transformers are certainly up to the job of driving my SD1 speakers.

In fact, my Krell KSA50 amp is now up for sale. ;)

[jandl100]

Mike (Shian7) has kindly sold me a Mullard ECC83 - arrived today (Thanks Mike :)) and I plugged it in to make a full set of 3 of the Mullards - the dang Leak just got even better - noticeably better transparency & 3D imaging (and I thought it was good before).

I'm rapidly coming to the conclusion that you ain't really heard your valve amp if you use 'stock' tubes - try NOS Mullards or Telefunkens and I think you'll be in for a very pleasant surprise! :smoking:

[Rare Bird]

Very nice, i used to have a pair of Leak 'TL12-Plus' monos, must have been nutz selling em thinking back..Prices have hit the roof a these dayz with the 'ST20' not that long ago you could pick one for about 250, your talking double now...

O god i'm getting itchy fingers again :(

[southall-1998]

Hello,

I know this thread is old. Sorry!

Does the Leak Stereo 20 have a ''euphonic'' sound?

[jandl100]

Nope - it's not a "traditional valve sound" at all. It's dynamic and detailed and perhaps a tad forward. I love 'em!

[MartinT]

Agree with that. It has perhaps the most fabulous, liquid, midrange of any amp I've ever heard. Not euphonic, just detailed and dynamic as Jerry says.

[Jonboy]

Excellent amps, i aggree that they can sound a bit forward but they can be breathed on to suit most tastes, a re-cap is par for the course.

I'm still missing mine:(

[Ali Tait]

Yes, I heard one several years ago that had had all it's components renewed. Sounded very good indeed, and unsurprisingly sounds quite like the WAD KEL84. I've read that the output transformers are very good indeed.

[tannoy man]

Hi Jerry, Ive been running a ST20 for about 15 years and feel the Rectifier GZ34 is very important to sound quality, please buy a Mullard, you will be glad you did.
The Pre amp is also crucial because of input sensitivity issues, Glen Croft will build you a Micro to specifically match the Leak at no extra cost.
PS
Ive owned 6 ST 20,s and the best sounding ones had the most original components.

[Jonboy]

the Rectifier GZ34 is very important to sound quality, please buy a Mullard, you will be glad you did.
.


agreed, but the original pre amp ain't that bad once rebuilt