Nick G modified Lentek Head Amp

[leo]

Grey and Grainy is typical with stuff filled with tants and ceramics (I won't mention any names ). Obviously analogue circuits are different to digital, analogue components used like caps is usually tuned by ear if used in say coupling, the hard bit is making sure you don't go too far overdoing it . I've heard some people find the bass can be a little soft with too many low esr caps in the chain, anyway good luck and keep us posted

[John]

Looking forward to your report Marco I remember hearing it before being mod it showed potential but agree with Marco thoughts The first words I said were it be worth getting this mod of course Marco already had plans that way

[Marco]

Hi Leo,

Grey and Grainy is typical with stuff filled with tants and ceramics (I won't mention any names ). Obviously analogue circuits are different to digital, analogue components used like caps is usually tuned by ear if used in say coupling, the hard bit is making sure you don't go too far overdoing it . I've heard some people find the bass can be a little soft with too many low esr caps in the chain, anyway good luck and keep us posted...

I think you're spot on, mate.

I suspect that Nick has used his experience to 'voice' the Lentek in a way that will make it sound more musical and less 'hi-fi'. It's a difficult balancing act to achieve, and shows yet again how one cannot build or modify equipment using measurements alone.

Trained and experienced ears are the order of the day.

As long as the Lentek hasn't lost its PRAT and 'boogie factor', which is why it complimented the 103 so well, I'll be happy

Marco.

[Marco]

Hi John,

Looking forward to your report Marco I remember hearing it before being mod it showed potential but agree with Marco thoughts The first I said it be worth getting this mod of course Marco already had plans that way

I'll definitely write something up once all the caps have burnt-in and the sound of the unit has 'fleshed out'.

The market isn't exactly flooded with good quality head amps, particularly ones that match the very popular DL-103 so well, so if the mods prove to be successful, my recommendation for people will be to buy a Lentek second-hand on Ebay, and have it modified. It'll be another viable option to explore.

Therefore, for around £150 one could have a top-notch active 'MC step-up solution' to rival the SUT approach that's likely to be superior to the built-in active MC stages in most commercial budget to 'almost affordable' preamps and phono stages, particularly for those who want to max-out the 103's unique sonic attributes...

Besides, I just LOVE using 'race-tuned', bespoke, hi-fi components and taking a different path from the norm!

Marco.

[lurcher]

Just so you all know, the reason its a bit "untidy" is that the entire thing is potted in silicon, so it had to be dug out before working on it. As said, I replaced the ceramics without thought, as I rarely find they deserve a place in the audio chain. The FKP I agree tend to be warm, but IMHO thats a good thing when combined with a unit what was a little hard sounding to my ears to start. The oscons were a experiment, In the past I would have used little black gates, and it possible I still will, see how Marco gets on, but it was the low noise character that I was most interested in.

TBH, it is noisier than I would have hoped for anyway, I have a thought to try something with a couple of 2sk369 in each chan.

[DSJR]

Grainy and grey? Not what you said when I complained of the same thing..... hmphh

Seriously though, the main problem with the supplied wires is age, rather than weakness and the phono plugs were ok, although not very posh looking (mine weren't original anyway).

I do feel a cap change coming on with mine though, although i wouldn't go with the aggro in changing all the resistors, let alone trying to shoehorn huge transistors in (what is deemed to be inadequate in the originals please?). I'm genuinely interested, not being sarcastic or critical, as regarding the caps, I suspect Lentek used what was available and of good consistent quality for the times.

Perhaps a parts-list please?????????

I look forward to reading the auditioning results while I plan world domination via Sowter instead (A23 is too dear and I have a box socketed up in readiness for the Sowters)

[Marco]

Hi Dave,

Grainy and grey? Not what you said when I complained of the same thing.....

I should've said 'grainy and grey' in comparison to the (£550) A23, when I originally tested them together

Look, as standard, for about £60 second-hand on Ebay, it's astonishingly good with a DL-103. However, as ever with anything in audio, things can be improved.

Seriously though, the main problem with the supplied wires is age, rather than weakness and the phono plugs were ok, although not very posh looking (mine weren't original anyway).

Similar to electrical components, Dave, the quality of plugs and cables has come a long way since the 80s. The stock items are distinctly poor by today's standards, and so needed replaced.

I do feel a cap change coming on with mine though, although i wouldn't go with the aggro in changing all the resistors, let alone trying to shoehorn huge transistors in (what is deemed to be inadequate in the originals please?). I'm genuinely interested, not being sarcastic or critical, as regarding the caps, I suspect Lentek used what was available and of good consistent quality for the times.

Re: the bit in bold. Did you mean caps or resistors instead, or am I misunderstanding you?

Nick will I'm sure explain why these were changed. Yes, Lentek would've used what was available at the time of decent quality, but remember that the quality of components these days, compared to those from nearly 30 years ago is more often than not far superior, so it's a no-brainer to upgrade the rather aged stock items.

Perhaps a parts-list please?????????

Did you miss this bit, daftee:

For reference, the component changes, wire and plugs in mine are as follows:

Ceramics were replaced with Wima FKP polyprop caps. Tants were replaces with OSCON SA caps.

The RCA sockets are CMC gold plated RCA sockets from HFC and the plugs are CMC-1036-WF RCA plug also from HFC. Cable is Shark double screened cable.

I look forward to reading the auditioning results while I plan world domination via Sowter instead (A23 is too dear and I have a box socketed up in readiness for the Sowters)

First impressions will likely be posted sometime tomorrow

Marco.

[Marco]

Hi Nick,

Just so you all know, the reason its a bit "untidy" is that the entire thing is potted in silicon, so it had to be dug out before working on it.

Yes indeed - obviously they didn't really want it to be opened up!

As said, I replaced the ceramics without thought, as I rarely find they deserve a place in the audio chain. The FKP I agree tend to be warm, but IMHO thats a good thing when combined with a unit what was a little hard sounding to my ears to start.

I agree, and I like your thinking on this

The oscons were a experiment, In the past I would have used little black gates, and it possible I still will, see how Marco gets on, but it was the low noise character that I was most interested in.

Sure, mate, I'll live with it for a while 'as is' and let everything burn-in. If I think there's mileage in more tweakery, I'll let you know, and you can vandalise it further

TBH, it is noisier than I would have hoped for anyway, I have a thought to try something with a couple of 2sk369 in each chan.

Like I said, it was 'noisy-ish' (read as in comparison to the A23) when I had it, although I never found this intruded on the type of music I played that suited its sonic characteristics (rock and pop), so if it's the same in that respect (or perhaps slightly better) but superior overall sonically, I'll be more than happy!

If you feel a couple of 2sk369s in each channel is liable to reduce noise, then that's something I'd be happy for you to fit as soon as possible, so if you've got any kicking around, feel free to pop them in before you bring the Lentek round

See you later, dude!

Marco.

[DSJR]

I'm going sight-fuzzy as well as deaf Marco so need the component list spoon-fed me. Caps I'm prepared for, as long as I can get the correct values (I like Wimas) Transistors I may well leave alone as long as the supplied ones aren't so poor (I doubt it). The cables already there look to be good quality screened ones and mine still had reasonable looking conductors. I do like the Shark wires though (their silver plated cable made excellent interconnects without sounding "silvery" to me, but that's another story).

By the way, mine wasn't potted, so I was lucky for once. The cap was super-glued (or similar) in place, so the board is a doddle to lift in my sample.

I'm not looking for the nth degree here, just a modernised old classic with a little less "character."

Would Mr Lurcher have tried it with a decent low impedance/noise power supply? Mine was too "hummy" for proper use and I might just change the 1000uF caps therein for some bigger ones. I have no idea until I've done it whether it'll make any difference. Pics to follow..

[lurcher]

I left it on battery, I think it would be hard to get a low noise supply that was floating in the way a battery does.

I didnt change the transistors thats what I found under the silicon, I suspect they may be the same types BD380 (I think, the numbers were rubbed off) just different case.