Collection Resolution Part I – Leak Tube Amplifiers

Hello to everybody,


today I am going to finalize a step in my life, which is not an easy to do. I have decided to sell my long term audio partners, which have enriched my life for the last 35 years in a way like no other audio components did. It took now almost five years decision to separate myself from this beloved items. I will here give this meticulously cared collection of audio history their last platform and this is the platform for sale and for me to say good bye. This is a bit emphatic, but there is no way out...

In General 

I will start with more common equipment from this brand and and will end with rare items, all are hard to find in this state today. So if you are interested to find some Leak amplifiers, you will get some of the best cared examples of their kind best possible state, technically but as well in very good optical condition. All amplifiers have been used and completely overhauled with best possible spare parts and as well in care of optical originality. NOS or new paper in oil- or electrolytic capacitors from major brands like Jensen or F&T. Carbon composition resistors from major brands like Alan Bradley, Beyschlag or others if possible in 2 or 3 watts qualities for the best smoothness. Solid core wires from different materials (silver, silvered copper and tinned copper). In some cases I have slightly upgraded the performance of the amps by introducing smoothing chokes instead of cheap power resistors. Power resitors  i. e., like cathode resistors are always green lacquered Rosenthal types, the best possible solution. Everybody is able to see at my photographs the standard of components. In difference to the many cheaply sold amps, here you don't find any useless replacement parts.

Leak Stereo 20 Power Amplifier

So we are starting with a very common amplifier from the Leak range, the well known Leak Stereo 20. This amplifiers are highly underrated, because they are so common. But its sound performance does not need any hiding comparing other tube amps, these are fantastic amplifiers if you can integrate them matching into a given chain. Like all British tube power amps from that period (1950ties to early 1960ties) the power amps are designed for highest input sensitivity matching their preamplification counterparts with extremely low output figures from the same brand. This attribute can create with modern preamps and their high output some real problems of hum and hiss. Generally all Leaks shown up with an extremely wide open soundstage when combined with the right preamplifier and matching output energy.

Leak Stereo 20 with power cord and RCA inputs

This shown amplifier was for almost 35 years my backup amp if I needed a physical small transportable amp, instead of a heavier and bigger pair of mono blocks like the below shown pairs. This amp can perform exceptional in a well balanced chain of vintage components, it is able to do everything which makes even sophisticated audio aficionados happy. This one is equipped with new RCA- contacts and underneath with carbon pots to balance the input energy.

Back side with Bulgin mains switch and banana contacts for the speakers

The overal condition of the chassis I would rate a good minus, I have seen and owned a few better ones, but technically this one is like new.

Underneath view with input carbon pots in the upper right corner

Smoothing caps are paper in oil from Siemens (sprayed in the matching gold tone), coupling caps are vintage Bosch and russian types, as the tubes are used but still with good emission and they are excellent sounding russian longline ER-types. Cathode caps are vintage Roederstein electrolytics.

Leak TL12 Plus Power Amplifier – Sold

This pair of recently completely rebuilt power amps is in incredible state, I would rate it almost mint. This is the best pair I did own since 1985 and I had several pairs since that time. Their chassis and paint work is like new.

Here again I have introduced input potentiometers (carbon pots) and solid rhodium plated RCA-contacts, smoothing caps are NOS PIO from Siemens bridged by Hammond smoothing choke, coupling caps are Bosch and Russian Types. Output terminals are changed to banana sockets. Resistors are carbon composition from different brands like Allan Bradley. 

This pair of Leak Tl12 plus is amazing sounding and one of the best pairs I had (I had in the late 1980ties ten pairs) and it comes with a well used quartet of the legendary Mullard Blackburn EL84 tubes, still well working but will need change in some time. If you are looking for a pair per amps from this type for daily use, these will give you another 35 years of service.

Leak TL10 Point One Power Amplifier   – Sold

Next offer will be a pair of predecessor mono blocks from the famous brand Leak, which entered a new market in 1955, the second amplifier line marketed with the ending "Point One" from Leak but this time for a growing private audio use. When they started in the late 1940ties to sell audio amplifiers it was a novum to have a power amplifier which was able to show such low distortion over the complete frequency range about 0.1%, this gave their early audio amplifiers their credit and name and made the brand successful in professional segments.

Here we have the series which was manufactured first in higher figures to satisfy demands in a growing market of the 1950ties. Leak wanted a physically smaller and cheaper produced unit than their exceptional and famous paragon, the legendary TL 12 Point One. With this amplifier Leak entered a growing market for the private audio enthusiast. With 10 watts output power and still the low distortion figures of 0.1% these amplifiers made the way for the success of the later mass products. Already all typical characteristics of the later production line (TL12, 25, 50 plus) were established here, but still realized with octal tubes of a former era. They introduced here rarely used power tube with this series of amps, the GEC KT61. Only a few amplifier designs were developed in the early 1950ties mainly by British brands, which used this exceptional fantastic sounding tube.

The set here shows up with marvelous condition for their age. Of course there are some minor chips and blemishes, particular at the black enamel of the Haddon transformers, but the overall appearance is breathtaking good in real. They are equipped with a new Quad of GEC KT61 (an additional pair of used ones, still good will be available as extra) and smoked gray military Brimar 6SN7GT. Input stage is changed to triode mode in order to decrease sensitivity with ECC83 from Philips. Power cords are cloth isolated types and with German AC-plugs.

The smoothing caps are again pro from Siemens and Bosch with a smoothing choke in-between (right lower corner). Underneath you will see completely rebuild unit with 2 watt carbon composition resistors from Beyschlag and coupling caps from Jensen. Power resistors are green glassed Rosenthal types. The amplifiers show with a switchable option between triode- and pentode mode. The power cords are again cloth isolated types and equipped with German ac-plugs.

The lucky new owner of this pair will be rewarded with a new quartet NOS GEC KT61s and additional with a spare pair of used ones from GEC (to be seen in the image above).

The next image brings us to the last set on sale, one of the best tube amplifiers in audio history and shows the sizes in comparing mode.

Three "Point One"-Amplifiers in comparison

Leak TL12 Point One Power Amplifier

And not least we look at a exceptional rare pair of the legendary Leak TL12 Point One mono blocks as they are hard to find today, but they were always rare at all times before. The shown sales brochure states that 731 units (mono) had been delivered to the BBC for their worldwide broadcast service, if we don't count any loss we have theoretically 370 stereo pairs. You might imagine yourself how many are today existing  in working condition after 71 years.  So you might as well imagine how many pairs are still working in such shown perfekt state like this pair.

These historical 12 watts push-pull triode connected amplifiers are simply the best sounding vintage valve amplifiers I could listen to within the last 35 years. They show up simultaneously with all so hard to find attitudes of smoothness, resolution, widest refined soundstage and almost unlimited control about any type of speaker. This incomparable service was the reason I did use these myself for the last 25 years in my own set up for every day listening. Some of the contenders could stand some single disciplines, a very few showed even up with benefits in part aspects, but there was by far nothing which could deliver such impressive completeness of sound. 

This pair was taken extraordinarily care about – like my eyesight, so is their optical and technical appearance just in a meticulous state. Nothing at the body has been changed, beside the two main switches (french air-force parts) for improved functionality. They come with all original accessories, like the rare two pin Bulgin bakelite plugs and cloth wire ac-cabling with the common three contact Bulgin-plug. They come with the original exceptional rare shielding cans. As all my amps both units have been equipped with chrome bell felt isolated feets. They come with their original sales brochure, which is a collector item alone.
They have been completely rebuilt with NOS Cornell-Dubilier-oil-capacitors (USA) in ceramic tubes, F&T cathode bypass caps, carbon composition 2 watts resistors. This pair has got new oil paper smoothing-filtering caps, these are impossible to find, so I did a small edition with copper housings and modern oil caps my self for a small group of TL12.1-aficionados worldwide. The new owner of course will get the leaking parts to complete originality.

The amps are equipped with original used  GEC KT66 tubes, these show up with 70% of their new emission, this means they are good for several years of daily use. They are actually configured for 15 ohm output, their multi layer secondary makes several configurations possible between 2 and 24 ohms, without loosing the potentials of the output transformer. A feature only seen at very complex made transformers with separate windings at the secondary found within this period (late 1940ties), like Partridge, Haddon, etc. for the Williamson Amplifiers.

I modified here the input with RCA contact to variablity with a stepped attenuator, with solid resistors housed in an octal plugged unit to match the existing preamp socket technically, but as well aesthetically the design of this amps.

Of course as well my darlings have been equipped with cloth isolated AC-cables of 1,5 meter length and German AC-contacts. The overal condition of this pair ist extraordinary good compared to units I have seen at Ebay since 1995. The most of them were sold not in matching pairs. If you are looking for a collectable and useable pair of amplifiers of this type, it will be difficult to find today any better on sale! No more comment on this.

I will sell this pair for an adequate offer, please accept that ideas around 2500 EUR per piece will not find response. This is the typical offers on Ebay for junk parts, wracks or restoration bases. The most amps offered are rusty or repainted, with new or foreign transformers or other restrictions to collectability, sometimes hidden to the customer. Here you know what you will get from somebody who knows better what the most people need to know. I don't have to make presents, I just want to find a fair deal for both side of interests.

These amps are huge, bulky and heavy (almost 20 kg each), so it might need two shipping crates/boxes, it depends on its destination. If these will find a new home in Asia I would recommend wooden shipping crates and will be able to make them, if fairly paid for the work. 

All my Leak amps can be delivered with their schematics showing the little changes made, the TL12.1 comes with original sales brochure and schematic.

I will be open for sensible made offers at heinze (at) kommunikation-i (dot) de.