Hong Kong Lowther Jazz 6L6 SET amp [Archive]

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Jazid

05-10-2019, 17:06

This little gem of an amp is built to an old circuit design, and uses two 6L6 output tubes run as single ended tetrodes. It is punchy, and very clear and fast, with astonishing bass given the size of it.

www.lowther.com/hk/Jazz 6L6 Amp.htm

It is made for Jazz and it delivers the hop factor in spades: if you want your music to get up and swing then this is the beast. Equally at home with big scale orchestral music it is a genuine giant killer. 8WPC, but as we know valve watts are different, it can shake the windows with my AN-Es. 4 and 8 ohm output taps, and a review on the Lowther hk website claims they even work well with Quad ESL63s [emoji15].

It came to me from Jake, the Lord Mortlock, (I grabbed a lot of his stuff when he downsized [emoji106]) and with luck he might report here? Jerry also knows and I think likes the presentation of this pocket rocket.

This amp is designed as a tube rollers delight! From their website:

You can safely use any tubes in the 6L6 family, such as 6P3P, 6N3C, 6L6, 6L6G, 6L6GA/B/C, 7581, 5881, 5932, 1612, KT66, EL37, WE350B ... etc.*6F6 also works. 6384 will need an adapter.

The 6SN7 driver tube can be replaced by CV1988, 6N8P, 6H8C, 6SN7M, or 6SN7W, VT231 directly. With an adapter made by us, you can use 12AU7, 12AY7, 12AV7, 12BH7, 5963, 5814, E82CC, ECC82, ECC802S...etc.* Or 6F8G with an adapter made by us.

The 5Z4P rectifier tube can be replaced by the 5Y3 family, U50, U52, U54, 5U4G, CV378, GZ34, 5Z4, 5T4 , VT-117, VT-74 or 5AR4 directly. The rectifier tube also changes the sound significantly.

I concur with the last statement, no doubts about it and easily measurable if that matters to you.

Currently fitted with a TAD GZ34, very decent it is as well. The drivers are Zaerix old stock 6SN7 (6N8P valves rebranded I think) which are reliable but can be sonically bettered with USA or Brimar offerings, and NNOS Brimar 6BG6 with adapters and top caps. Lovely valves [emoji7], I doubt you'll want to change them, and still affordable new though there's years and years left in this pair. There's plenty of new production offerings to try as well. Just one note of caution: big bottle Chinese CV181 tubes will not fit, not enough space.

Never on the market, no longer available at $500 with plain vanilla Chinese valves, plus shipping plus import duty/VAT, I am asking £450 for this very tidy example, plus shipping or collect tomorrow in Tonbridge, or from W. London [emoji16] where you can hear its magic for yourself. I don't have original packaging but will pack very well.

Thanks for looking https://uploads.tapatalk-cdn.com/20191005/ebe985bd48fbca93b5de18c66d0e6c22.jpghttps://uploads.tapatalk-cdn.com/20191005/61c180bf4a863628acb2872ce1a4b48b.jpghttps://uploads.tapatalk-cdn.com/20191005/2aa575334a2a0eb966ce527cb52b71c9.jpghttps://uploads.tapatalk-cdn.com/20191005/5b30adbaf5c248a61dba69b4ee90498b.jpghttps://uploads.tapatalk-cdn.com/20191005/8f3835411871ac2fa146c60b30b73fd3.jpghttps://uploads.tapatalk-cdn.com/20191005/82409ea33ff4a87f84777de2034fab52.jpghttps://uploads.tapatalk-cdn.com/20191005/0ab0daffff6d97b2b0b4cdd769c9c131.jpg

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walpurgis

05-10-2019, 17:20

Great looking bit of kit James! :)

Westendboy

05-10-2019, 17:52

Would like to have a listen to this but can’t make Sunday

Westendboy

10-10-2019, 03:59

I’ve sent you a pm

jandl100

10-10-2019, 08:58

Fabulous amp - I sold this to Jake LordMortlock.
I can't recall why - what a daft thing to do!
Superb transparency, detail and dynamics. And as fast as a turbo-charged fast thing. A real treat for the lugholes.

Audio Al

10-10-2019, 09:16

jandl100

10-10-2019, 09:17

:doh: I knew there was a reason.

Audio Al

10-10-2019, 09:22

:doh: I knew there was a reason.

:lol::D

Lawrence001

10-10-2019, 12:14

When I first saw this I thought it was a Single Ended Triode amp, but looking again, does the T stand for Tetrode? Or are they Triode strapped?

Jazid

10-10-2019, 12:24

Nope, pure single ended tetrode.

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Westendboy

10-10-2019, 14:22

Hi James, have you checked your inbox

Jazid

10-10-2019, 18:58

Hi Keith,

Apologies for the delay, following a request from an AoS member (Lawrence) to check for hum as he uses sensitive speakers I have listened and there is low level hum audible from about 1-2ft from the amp. Bear in mind I use higher sensitivity AN-E (allegedly 95dB/m). This is perfectly normal and acceptable in a modestly priced valve amp. However I settled down to listen and got lost in the music because it is so damned good, and when eventually I went to turn it off an hour later the hum had become louder and was now just about audible from my listening position. I don't know if it was always like that as I rarely get a chance to listen for more than a short session, so it could be just how it is. Either way clearly this ain't going to cut it with sensitive horn speakers, and I don't think it right that the amp should hum more when warm anyway so I played around swapping different valves - no change, and then popped the back off and uncovered some suspect solder joints which have all been re-soldered, but still no change. I am now going to re-cap the power supply as it gets hot in there so it might help and can't hurt. This amounts to 5 capacitors none of which I had in stock so I am waiting on RS. Rest assured the capacitors I have selected are all better spec than the originals (which were already decent quality). Where apropriate I have modestly increased capacitance, though obviously not for the 47uF after the rectifier!

When this is done and properly soak tested I shall report back, it could be that the hum is a design issue and remains, it could be tired electrolytics, it could be something else, I just can't say at the moment, but I will not release it until I feel secure that is is behaving correctly, so sorry for the inevitable delay - its for your benefit chaps :thumbsup: After that I have promised first dibs to Lawrence and his Hornings, Keith you are next in line to pop over for a listen, and Karl from LH is third in line.

Whoever gets this amp is a lucky bugger I swear!

Westendboy

10-10-2019, 21:21

That’s fine James, good luck with your investigations!

Jazid

12-10-2019, 19:03

Just a quick update, I ordered caps from RS because they were in stock, and it appears that four were in stock and delivered and installed, but one IS technically in stock but in ... Japan! Anyway by the end of the week... Further progress, the earthing was suspect and I have improved safety there and implemented proper star grounding so hopefully things will look up. I'll document the tweaks in due course although muggins forgot to take 'before' pictures. Duh!

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Jazid

05-01-2021, 18:59

Back up for sale as I MUST shift stuff. Modestly upgraded in so far as the PSU caps are better than original, star earthing is way better than stock. There is still low level hum, less now than as written above and really nothing to concern anyone at the price point, I think it's due to the transformer orientation, and I'm not about to alter that. It is solid, valves are solid, absolutely as described in my original post, sweet little amp. Available for postage as an extra cost - I'll pack it well for sure, or for properly socially distanced collection from W14 West London if you are passing on work. Pics of innards available to interested parties via email - PM me your contact and I can send.

anubisgrau

05-01-2021, 19:37

PM sent

Lawrence001

05-01-2021, 22:07

Think it sold within minutes on the Wam to a former owner.

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philv

14-07-2024, 13:53

Thanks