View Full Version : It's that bloomin' Lentek Head Amp Again...
I don't mind being challenged if it isn't too expensive to remind myself on memories of old products, and Marco did it again with the above mentioned beastie :)
It took a little while to locate one and even longer to actually receive it, but this morning a well packaged example arrived, boxed and with its instructions, but with the sh*tiest phono plugs and soldering I'd seen in years - made my own soldering look amazing..
http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1357.jpg
This brought up an issue I have with amateurish domestic tinkering with these sorts of things. If you cannot solder - DON'T - until you've had some practise and/or training. The rest comes with experience... I had a pair of the better Neutrik phono plugs spare so, after trimming the ghastly mess back, I carefully fitted these on. The fixed cable uses copper stranded core with a foamed insulation and a woven (not that tightly) tinned(?) screen.
Under the top cover-casting, there's an internal cover held on with one screw, which is so tight fitting I found it a little difficult to remove. I found a carefully inserted Stanley Knife blade was able to pop it open.
http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1358.jpg
The internal battery was a 2007 dated Duracell PP3 type, which I removed and put in for recycling. The business part of the headamp is a small circuit board with a cover glued in place. This board is so small I reckon there's an op-amp IC or two in there, but could be wrong. I didn't wish to delve further and wreck the thing so soon after buying it, so I left well alone. Here's a pic of it ready to be put back together- By the way, I remember the battery test LED being green on the one's I sold and used (could be my memory though), but this one's red.
http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1359.jpg
So, what's it sound like????
I'm stunned that Marco finds it so good with the Denon, as the loading is "only" 100 Ohms. As the Denon 103 has a higher output impedance than many MC's (42 Ohms I think), I'd have thought that 420 - 500 Ohms loading might have been better. A bit of a thorny issue here I reckon, as the "correct" loading as seen by the cartridge may not be what one likes the sound of..
Anyway, I removed the trusty AT630 and slipped the Lentek in its place. Firstly, there's slightly less hum (the AT trannie is very fussy where it's placed or hung), but to counter that, there's more noise, not unpleasant, but rather more than the Croft phono stage.
Used with the Supex 900E Super, the sound was flat, dead, but with slightly better bass and treble control - the AT is a bit loose here. I didn't like the results at all, although I'll admit the "grain" I complained of wasn't too obvious. I then returned to the Stilton OC9 and the mid-depth came back to a degree. The thing is though, the overall sound was like the V15III I resurrected recently, utterly neutral, but with a slightly dead, almost nasal quality to the sound which MC's don't usually have at all and which isn't really "accurate." I just found the sound seems to have degraded the wonderful "Croft" phono-stage qualities I crave so much.
Early days yet and I shall carry on with the Lentek, as apparently this sample lay in a drawer somewhere powered up, so the battery ran down, probably several years ago judging by the battery date. I'm enough of an audiophool to leave the setup as it is for a few days just in case the units need to "adjust" to each other (:lol:). I'm leaving turntable quality out of this for today, as it's the mid that drew my attention and both cartridges do better than this with the AT into the Croft...
Hi Dave,
Quite clearly, I'm a bad influence on you! :lol:
I don't mind being challenged if it isn't too expensive to remind myself on memories of old products, and Marco did it again with the above mentioned beastie...
Sorry, guv.... :o :eyebrows:
I'm stunned that Marco finds it so good with the Denon, as the loading is "only" 100 Ohms. As the Denon 103 has a higher output impedance than many MC's (42 Ohms I think), I'd have thought that 420 - 500 Ohms loading might have been better.
Yup - folk have said that before. No doubt it makes perfect technical sense, but the fact is Keith Aschenbrenner designed the A23 to match the 'cooking' DL-103, and Dave Cawley (when I took it down to him) measured its loading value at just a shade over 100 Ohms, so quite clearly such a setting is no accident ;)
And, without question, that value does seem to suit the 103 very well indeed, as not only the Lentek sounds fab with the 103, but also the A23 - both loading it at around 100 Ohms! There are also too many delighted users of the A23/DL-103 combo for the 100 Ohms setting not to be 'right'......
Furthermore, no matter whether I use the 'cooking' 103 or the 103SA, with a different coil resistance value, the results are equally as good with the A23 or the Lentek at 100 Ohms, allowing of course for the fact that the 'SA' is the better cartridge and the A23 ultimately the better step-up device, sonically.
A bit of a thorny issue here I reckon, as the "correct" loading as seen by the cartridge may not be what one likes the sound of..
I've heard the 103 loaded at 500 Ohms and it just sounds brighter, not better. I quite like it at 250 Ohms, though, when I heard it through another phono stage with variable loading, but it wasn't necessarily any more preferable than what I get at around 100 Ohms with either the A23 or the Lentek.
As always with these things, it's best just to use your ears! And of course much depends on the sonic signature of the partnering phono stage and T/T, and how this synergises with that of the Lentek.
Anyway, I removed the trusty AT630 and slipped the Lentek in its place. Firstly, there's slightly less hum (the AT trannie is very fussy where it's placed or hung), but to counter that, there's more noise, not unpleasant, but rather more than the Croft phono stage.
Used with the Supex 900E Super, the sound was flat, dead, but with slightly better bass and treble control - the AT is a bit loose here. I didn't like the results at all, although I'll admit the "grain" I complained of wasn't too obvious.
Interesting.... At least it had some redeeming features! :lolsign:
Remember that my enthusiasm for the Lentek is derived solely from the fact that it matches the 103 so well, to my ears, *NOT* as a result of hearing it with any other cartridges. You'd need to get hold of a 103 (and an appropriate arm and headshell for your T/T) before you'd hear anything like what I'm experiencing........
However, it'll be interesting to see how you get on using it with the OC-9, etc, although I'm not expecting much!
Early days yet and I shall carry on with the Lentek, as apparently this sample lay in a drawer somewhere powered up, so the battery ran down, probably several years ago judging by the battery date. I'm enough of an audiophool to leave the setup as it is for a few days just in case the units need to "adjust" to each other
It certainly won't do any harm. Rather bizarrely I've noticed that if you leave the Lentek switched on for a few hours, it seems to sound better than when it's been switched on from 'cold', although of course this does nothing for battery life!
Anyway, Dave, respect for trying the little beastie. Keep us posted how you get on :cool:
Mine is currently being fettled by Nick Goram, so watch this space!
Marco.
Rather bizarrely I've noticed that if you leave the Lentek switched on for a few hours, it seems to sound better than when it's been switched on from 'cold', although of course this does nothing for battery life!
I read somewhere that Duracell brand batteries (formerly Mallory) were preferred for use in the Lentek.
A new avenue for some research: 'battery rolling'. :scratch:
Regards
Let's see what Nick can do with yours - and advice from you or he please, on how to safely and carefully remove the little circuit-board cover...
Whatever, it's one of those things you should have handy, 'cos you'll never know when or if it'll be needed.
I've re-capped, dioded and re-valved the X10-D and now Clive has paid in my cheque (thanks sir!) and if you'd like, I can post some before and after pics of this spring-cleaned and much clearer and less dirty sounding device...
All this pales into insignificance compared to the dramatic transformation (for the better) of the Quad 33 preamp, which sounds lovely as a line-buffer and with the tone controls still in use..
http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1355.jpg
I read somewhere that Duracell brand batteries (formerly Mallory) were preferred for use in the Lentek.
A new avenue for some research: 'battery rolling'. :scratch:
Regards
I'd rather convert the simple 12V 25VA supply I'm making to 9V and use that TBH.
I'm probably wrong, but the Mallory Duracell was, I think, the only Alkaline type PP3 battery on the market back then..
I read somewhere that Duracell brand batteries (formerly Mallory) were preferred for use in the Lentek.
Hahaha.... You're joking, right?
Dave,
Yep, you're right, it's a handy little device to have regardless....
Good result on the Quad.
Nice pic of your system (at last)! ;)
Marco.
Hahaha.... You're joking, right?
Marco.
http://i132.photobucket.com/albums/q8/DSJR_photos/LentekInstructions.jpg
Hahaha.... You're joking, right?
No, I'm sure I did read that somewhere.
As for battery 'rolling', well why not? Not too expensive to try. If people can hear large differences between bits of wire, resistors, capacitors and other components, then why not batteries?
Regards
http://i132.photobucket.com/albums/q8/DSJR_photos/LentekInstructions.jpg
Yes, that supports your previous post. But I think I read that the Mallory/Duracell brand sounded better compared with other brands (Ever Ready or far eastern products). I have no experience of this however.
Regards
Yes I've got one of those too, but that doesn't necessarily mean that a Duracell battery is liable to 'sound' better than any other :eyebrows:
It's the one I'm using, though - but only because I find Duracell batteries generally last longer than others!
Barry,
As for battery 'rolling', well why not? Not too expensive to try. If people can hear large differences between bits of wire, resistors, capacitors and other components, then why not batteries?
Indeed. When I get the Lentek back, I'll battery-roll it to death! :eyebrows:
Marco.
Yes I've got one of those too, but that doesn't necessarily mean that a Duracell battery is liable to 'sound' better than any other :eyebrows:
It's the one I'm using, though - but only because I find Duracell batteries generally last longer than others!
Marco.
How do you know Marco? You try out different cables - why not batteries?
Regards
See the recent edit on my last post, daftee! :lol:
Marco.
Ali Tait
09-06-2010, 20:21
Several folks have in the past noted differences in the sound of different batteries used for battery bias on the front-end or driver valves in amps.
How do you know Marco? You try out different cables - why not batteries?
Regards
Maybe the different capacity ? some vary in mAh, different cell types may influence things , not sure tbh but anythings possible in this hobby:eyebrows:
Indeed - I'm up for it! :eyebrows:
Marco.
Rare Bird
09-06-2010, 20:39
http://i132.photobucket.com/albums/q8/DSJR_photos/DSCF1355.jpg
Wow! nice Marantz oops i mean Micro Seiki CDP
Take a CD94, strip off the front panel, replace or at least modify the power supply for relay switching, add more copper, a thick milled top plate, loads of solid rosewood and tranny coupled XLR output from before the audio-output stage and there you have it.. :). new it sold for £2800, I bought mine in 1994 for £1100. A couple of years ago I'd have valued it at £500 or less, although now, with a good working CD-M1 mech/laser and the 1541 DAC chipset it may start to appreciate perhaps?
Rare Bird
09-06-2010, 21:12
Take a CD94, strip off the front panel, replace or at least modify the power supply for relay switching, add more copper, a thick milled top plate, loads of solid rosewood and tranny coupled XLR output from before the audio-output stage and there you have it.. :). new it sold for £2800, I bought mine in 1994 for £1100. A couple of years ago I'd have valued it at £500 or less, although now, with a good working CD-M1 mech/laser and the 1541 DAC chipset it may start to appreciate perhaps?
Yeh i always fancied one..What that Rega Planar 3 plinth under it for :lolsign:
Glad you can have a laugh Dave
Keep it, Dave - it's a proper CDP from the days when proper CDPs were made! Mark from Audiocom would make it into a veritable giant-killer ;)
Back to the Lentek...... Nick G's going to build one of these for me to listen to and compare with the Lentek:
http://users.ece.gatech.edu/mleach/headamp/
Sounds interesting! :)
Marco.
Keep it, Dave - it's a proper CDP from the days when proper CDPs were made! Mark from Audiocom would make it into a veritable giant-killer ;)
Back to the Lentek...... Nick G's going to build one of these for me to listen to and compare with the Lentek:
http://users.ece.gatech.edu/mleach/headamp/
Sounds interesting! :)
Marco.
Marco,
I know someone who's been down that route, a few versions of the Leach were trialled against my Hagerman Piccolo headamp. The Piccolo came out on top. It's very slight clinical nature can be tweaked out with more suitable capacitors, you then have a superb and flexible headamp
Clive
Cheers, Clive. I'll bear that in mind :)
What I find is that transformers and active head-amps both have an intrinsic 'signature' which they impart on music.
Overall I generally prefer transformers, but certain head amps, like the Lentek, have a charm all of their own and offer a different, equally sonically satisfying presentation.
It's nice to have the choice of both!
Nick was also talking about a doing a valve head-amp at some point. He said that he heard one once and it was absolutely stunning!!
Marco.
Clive,
I suggest you try some resistor rolling on the load impedance switch in the Piccolo. I fitted some same value (470R) Schinkohs to replace PRPs and the difference was amazing with my Troika.
Clive,
I suggest you try some resistor rolling on the load impedance switch in the Piccolo. I fitted some same value (470R) Schinkohs to replace PRPs and the difference was amazing with my Troika.
Chris, I'm the resistors will make a difference and improve the sound, I was going to resistors to my comment but either got lazy or decided not to complicate things.... Actually I'm using Deccas/Londons at the moment so I don't use my headamp or SUTs.
The Piccolo does make life easy for anyone using multiple cartridges too, it should be said. Not all at the same time though. :)
Can I stick me muddy paws in again?
Marco, if loading the Denon with 250 - 470 Ohms makes it brighter, I suspect it's because this latter loading makes the response "flat" as this is one area the 103 excelled at - a pretty neutral response despite the conical stylus tip.
I'm sure that step-up transformers may add something of their own, but thanks to you guys I'm beginning to see the slightly wider view that domestic audio possibly needs that indefinable "something" to enable suspension of disbelief. A fully clinical and "truthful" monitoring system may not always be enjoyable - one reason why I've had some stick elsewhere for supporting Harbeth's monitors, passive or not, as one gets a pretty honest sounding box which can be listened to for hours on end with much enjoyment and no fatigue..
That simple head amp design linked to by Marco *should* be fine, as the circuit is so simple. I can't be a*sed to take the lid off the AVI preamp, but the "good" transistor numbers seem very familiar, as the AVI output stage has those (I think) biased heavily into class A, judging by the heat they give off...
Next up - I've FINALLY drilled the TD125 arm-board and mounted the R200 to it. I'll finally have the TD125 going after eighteen months and this is one springy belt-drive I want to get out of my system :)
P.S. Marco,
The Lentek's sound DOES improve after an hour or two, I've heard this twice now :)
There's still a quality to the sound I remember from prior to Linn and Naim taking over my (and KJW1's) life back then, but I can't describe it - a certain lack of "intimacy?")
Hi Dave,
The Lentek's sound DOES improve after an hour or two, I've heard this twice now...
Nice one - I thought that I might be imagining things!
There's still a quality to the sound I remember from prior to Linn and Naim taking over my (and KJW1's) life back then, but I can't describe it - a certain lack of "intimacy?")
Admit it, it's not as bad as you remembered it to be though, is it? ;)
Marco, if loading the Denon with 250 - 470 Ohms makes it brighter, I suspect it's because this latter loading makes the response "flat" as this is one area the 103 excelled at - a pretty neutral response despite the conical stylus tip.
So are you saying then that loading the 103 at 100 Ohms doesn't result in a flat response?
Mmm... I'm not sure about that, based on what I've heard from that cartridge over many years in many different systems. Also, I can't see Keith Aschenbrenner designing the A23 (which loads the 103 at just a shade over 100 Ohms) not to have a flat frequency response..... :scratch:
I think it's probably as much to do with system synergy as anything else, and 100 Ohms seems 'right' to my ears over a wide range of different systems, and I'm not alone in that respect.
That simple head amp design linked to by Marco *should* be fine, as the circuit is so simple.
Well we'll see what Nick can come up with. I'm sure he'll take on board Clive's remarks, as I know he's following this thread with interest.
So have you still got the Lentek in circuit or is the X-10D vying more for your attention tonight? :cool:
Marco.
Ali Tait
11-06-2010, 17:30
I'm sure it'll be excellent Marco,like most things Nick makes!
Cheers, Clive. I'll bear that in mind :)
What I find is that transformers and active head-amps both have an intrinsic 'signature' which they impart on music.
Overall I generally prefer transformers, but certain head amps, like the Lentek, have a charm all of their own and offer a different, equally sonically satisfying presentation.
It's nice to have the choice of both!
Nick was also talking about a doing a valve head-amp at some point. He said that he heard one once and it was absolutely stunning!!
Marco.
I've been meaning to build one for the last five years or so. Have got the parts just need to pull my finger out!
Regards
The Lentek is still in circuit and had a pasting earlier today. It treads a very fine line between Hifi and music and I'm still finding it hard to pin down... :scratch:
Every time I decide to put the X10 into service I have a great headphone session with the Quad 33/D-60 and can't be a*sed to change it over to be honest. I think the X10 as it currently is may well be better - we'll see..
My first fully DIY project - a 12V AC supply as described on Rock-grotto - Simple XP Supply. Cutting out the apatures for the IEC socket and switch were a PITA as I have no skill, but if you don't look too hard it's ok. I just have to finish it off in the morning and await the big bang with interest (my eyes get very tired and I should make more use of my mid-distance specs...).
The next thing is to finally get the TD125 going. I drilled the arm board and found some suitable spacers for underneath so I could get the nut firmly tight (I still have a Rega sized spanner made for me by a grateful client...). It's a bit big to smuggle indoors though :mental:
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