Leak TL/12 Plus / Point One Plus
Tony L
Administrator
I haven’t done any comparisons yet. My plan is to just run them in the upstairs system for a while, at least a month or two to let them bed in/make sure all is spot-on with the rebuild etc and then I’ll stick the Stereo 20 back and confirm or deny what I think I hear.
My impression so far is that they are a little crisper, more forward and dynamic, e.g. they seem to hit the snare harder on say Jarrett Trio ECMs (the drums on Yesterdays are incredible (what planet Amazon’s algorithm is in today I have no idea!)). A little tighter and grippier in the bass too, not that it was missing at all previously. The Stereo 20 has a lovely ‘lush’ slightly stereotypically ‘valve’ sound, but not much in it at all and arguably as much to do with the specific valve sets as anything (I have a lovely ‘64 set of Blackburn Mullard EL84s in the Stereo 20 and I’m using Russian 6p14p-ERs in the TL12 Plus, and they do sound different).
When I go back for a comparison I’ll stick the Russian power valves in the Stereo 20. There is also a difference in small signal valves where the TL12s use an EF86 and an ECC81, the Stereo 20 3xECC83. Even so far more alike than different, they really are cut from the same cloth. I’m a bit nervous of trying the Mullard EL84s in the TL12 Plus as they are worth LOLprice and they do run them a bit harder than the S20.
My prediction is the TL12 Plus will suit the LS3/5A better, the Stereo 20 the JR149s, though I’ve not even tried the 149s with the TL12s yet. Regardless I don’t want to over-emphasise any perceived difference here, what I’m feeling really is at the ‘tube-rolling’ level. Both amps are very much variations on the same theme. I think the TL12 Plus look a lot nicer, what with having a proper front, back, and two sides etc! I’m certainly planning to keep both amps.
PS I’ve not mentioned cost yet, but I may as well document it for completeness:
Amp #1 (local auction): currently owes me about £50 as I’ve already sold some stuff from that lot, though I still have a Point One preamp to sell which will push it negative.
Amp #2 (eBay): £690 including shipping, and came with a boxed Varioslope preamp to sell.
Parts: between Hi-Fi Collective, my existing stash of K40Y-9 caps, various 1uF caps, Bulgin octal plugs, speaker connectors, interconnects and a few other things I’m at around £225 or so.
So, around £965 not including valves. I did get a decent EF86 collection (two in each preamp too), a Blackburn GZ34 and two (sadly different) pairs of Mullard EL84s, all of which seem fine, so I am actually a few £hundred up here. I’ve also got two preamps to sell on, so if I can get £100 each for them minus the EF86s, which is not that unreasonable, it starts to look like a real bargain at £765. It would obviously have been *a lot* more expensive had I paid someone else to do it. Nowhere near as interesting or rewarding either.
PPS Amp #2 owes my grey Stereo 20 a mint Bulgin mains plug too.
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I assume you will try them with the Tannoys also. I do find certain classic systems fascinating; it is too much faff for me but I reckon my current system will be considered classic in the near future.
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Tony L
Administrator
Yes, that is on the list. The Stereo 20 works nicely down there, though only with the passive so it turns the system into digital only (my Verdier pre is just too loud even on its lowest setting).
snowman_al
pfm Member
I guess as it is a week since you swapped over the boards and there have been no negative reports from Tony L it's safe to assume it is resolved?
I do hope so and a well done for persevering.
I do hope so and a well done for persevering.
Tony L
Administrator
Yes, they have quite a few hours on them now and seem to be working perfectly. I guess it was either one of the Allen Bradley carbon 3m3s or a less than perfect joint somewhere.
I’m very happy with the amps now and in a way I’m pleased I went to the lengths I did in removing the boards etc as I know they are clean and the upper wiring is good etc. I think they currently stand as a decent sympathetically restored pair of TL12 Plus.
I’ll not do anything to them for a while now. I want to be sure they are rock solid before thinking about anything else. Ultimately I would like to gut and re-stuff the big can-cap, but only if I’m 100% sure I can’t screw it up! Either that or find a perfect paint match as I’d be happy to boil them or whatever to soften the tar/wax gunk up in that case.
I’d also very much like to understand the extra fuse Will/Radford Revival added to his restoration, e.g. value, what exactly it protects against, where/how it is wired-in etc. If it prevents a proper melt-down in the case of a EL84 failure/short or whatever then I think I’d far prefer to do that than the diode mod (which I haven’t done yet). I know most modern valve amps have more than a simple mains fuse.
PS As stated somewhere way upthread I reduced the 2A fuse in the voltage selector specified on the schematic down to a 1A and they are holding-up fine so far. I wonder if I could get away with lower still?
I’m very happy with the amps now and in a way I’m pleased I went to the lengths I did in removing the boards etc as I know they are clean and the upper wiring is good etc. I think they currently stand as a decent sympathetically restored pair of TL12 Plus.
I’ll not do anything to them for a while now. I want to be sure they are rock solid before thinking about anything else. Ultimately I would like to gut and re-stuff the big can-cap, but only if I’m 100% sure I can’t screw it up! Either that or find a perfect paint match as I’d be happy to boil them or whatever to soften the tar/wax gunk up in that case.
I’d also very much like to understand the extra fuse Will/Radford Revival added to his restoration, e.g. value, what exactly it protects against, where/how it is wired-in etc. If it prevents a proper melt-down in the case of a EL84 failure/short or whatever then I think I’d far prefer to do that than the diode mod (which I haven’t done yet). I know most modern valve amps have more than a simple mains fuse.
PS As stated somewhere way upthread I reduced the 2A fuse in the voltage selector specified on the schematic down to a 1A and they are holding-up fine so far. I wonder if I could get away with lower still?
Radford Revival
Trade: Radford Revival
FWIW I use a 2A fuse for an entire STA25 so I would think a 1A fuse would be fine on a TL12+. A common 1A fuse in theory will pass 1A indefinitely and a single TL12+ certainly isn't a 250W load! A whole STA25 draws about 0.8A (from memory, I have the actual figure written down). It's not like a TL12+ has a big inrush spike either (due to the GZ34).
I think I just put a fuse in line with the centre-tap of the output transformer on those TL12+s, it just felt better than having nothing at all. Something like a 160mA fuse would probably do, though I fully admit this is based on no calculation. On the STA25 along with an active protection circuit I use a T250mA on each channel as a last resort which I eventually settled on based on experience and balancing nuisance blowing and protection - it seems to work too and has saved a few amps from valve meltdowns.
Tony L
Administrator
I was baffled by the 2A fuse given a Stereo 20 has a 1A! They both could expect to be feeding a preamp, so 1A is likely over what is needed stand-alone.
I do like the idea of the output transformer fuse. I’ll very likely do that at some point.
toprepairman
pfm Member
Hi Tony.
Some time now since we heard about the TL's, so after a reasonable amount of time, how do you feel they stack up against the ST20?
Some time now since we heard about the TL's, so after a reasonable amount of time, how do you feel they stack up against the ST20?
Tony L
Administrator
I’ve still not got around to doing a direct comparison yet! The one thing I can say for sure is I really like them. My impression is they are very similar (as one would expect) but a little more forward and dynamic/punchy, they just give the impression of having a little more headroom. As a system they work superbly well with both the LS3/5As and JR149. If I was forced to decide which to keep right now I’d keep the TL12+, but I think looks plays a part there too! I will have a proper A B at some point fairly soon.
PS The choice of which pairs of EF86 and ECC81 makes a substantial difference, thankfully I have a good stash of different Mullard dates and construction types.
Tony L
Administrator
I mentioned in the ‘interesting eBay listings’ room a few days ago that someone was making steel baseplates for vintage Leaks. Anyway, as evidenced by the picture above I bought some for the TL12 Plus and my Stereo 20 as it finishes them off, gets them a heck of a lot closer to current safety regs etc. They fit pretty well, I had to finagle the Stereo 20 one a bit (I needed to drill the holes out larger), but the TL12 Plus fitted without issue, look neat and solid, and I doubt they impede ventilation too much. I’d definitely recommend them as they protect the tag boards and components from accidental damage plus end users from nasty jolts (capacitors in a valve amp can hold some very high voltage for quite some while even if disconnected from the mains). I’d also far prefer to pack a Leak for shipping with these bases fitted. Far less prospect of damage. Here’s an eBay link.
PS I was surprised they fitted my TL12 Plus so well as the F&T dual cap I fitted (pics upthread) does hang down a mm or so, but luckily their mounting band could be nudged into one of the ventilation slots! Everything is a nice flat and solid fit here.
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Barrymagrec
pfm Member
A slight improvement might be to replace the ventilation slots with upward pressed louvres, this could improve the ventilation without increasing the size of the slots, improve the strength as no material would be lost and possibly reduce any hot melted wax dropping through the slots in the case of an overheating component.
Just a thought.
Just a thought.
Radford Revival
Trade: Radford Revival
.
Radford Revival
Trade: Radford Revival
Just for posterity
Tony L
Administrator
I wondered if it was someone connected to you making them as it looked very similar to the ones you made for your refurb.
You should market them, plus the speaker terminals, switch plate etc IMO. There are always lots of us in the DIY community refurbishing these classic amps and these are clearly parts folk want and can’t easily make for themselves.
You should market them, plus the speaker terminals, switch plate etc IMO. There are always lots of us in the DIY community refurbishing these classic amps and these are clearly parts folk want and can’t easily make for themselves.
Radford Revival
Trade: Radford Revival
Indeed, I think this has spurred me on!
Barrymagrec
pfm Member
Feel free to use my louvre idea if you think there`s any mileage in it.
Tony L
Administrator
For my purpose a flat base was required due to my mounting of the big F&T cap:
This is a problem that will need addressing by anyone who doesn’t fancy slicing up or gouging away at the original Leak cap (which is essential to retain the amp’s original aesthetic). Basically the new cap needs putting somewhere, and there aren’t a lot of available options that are non-destructive to the chassis. It ended up touching the flat baseplate, but not bowing it (which surprised me, I was expecting it to!).
This is a problem that will need addressing by anyone who doesn’t fancy slicing up or gouging away at the original Leak cap (which is essential to retain the amp’s original aesthetic). Basically the new cap needs putting somewhere, and there aren’t a lot of available options that are non-destructive to the chassis. It ended up touching the flat baseplate, but not bowing it (which surprised me, I was expecting it to!).