Nick G modified Lentek Head Amp

[Arkless Electronics]

Yes, indeed, headamps are a very niche product. There days there are so many mc compatible phonostages around that there seems there's hardly any point in getting a headamp. Of course, most valve phonostages are mm only so some kind of headamp or step-up is essential if you want to use an mc cartridge, but I have no idea what they're using - they're certainly not buying a lot of headamps or step-up transformers from me!

Nor from me! Head amps that is... I don't make SUT's... But of course if a Lentek one comes up it is snatched up in minutes cos it has the "approved brand name"! Well I'm making my forthcoming full function hybrid pre (a shoot off from this will be a phono stage and a line stage) as MM only due to the current fad for using MM stages with separate head amps or (more likely) SUT's, so it will be interesting to see how that goes.... I'll probably offer a matching head amp for that which takes its power from the main unit and maybe a MC only version, which would be a fair bit more expensive as it would probably need an external PSU. I generally make MM only or MC only phono stages BTW as I consider it too large a compromise to do otherwise.

[Firebottle]

It's popular because it sounds bloody good, and it's cheap!

Marco took his to MiBO so I got to hear for the first time what the appeal is about the Lentek. I swapped my Firebottle 2000 head amp in directly afterwards as a comparison (who wouldn't ) and it was a very interesting comparison. Not a huge difference as I may have been expecting.

I thought the FB 2000 gave a 'smoother' presentation but the Lentek majored on boogie factor and musicality. Difficult to quantify 'musicality' but certainly a good sound

[337alant]

Here are some notes I made when I was repairing Steve's
I should have sketched it out at the time
Note i dont know what the NPN transistors are as there is no markings




LENTEK HEAD A MP by Alan Towell, on Flickr

Pic of the underside

IMG_2683 by Alan Towell, on Flickr

Alan

[Marco]

Marco took his to MiBO so I got to hear for the first time what the appeal is about the Lentek. I swapped my Firebottle 2000 head amp in directly afterwards as a comparison (who wouldn't ) and it was a very interesting comparison. Not a huge difference as I may have been expecting.

I thought the FB 2000 gave a 'smoother' presentation but the Lentek majored on boogie factor and musicality. Difficult to quantify 'musicality' but certainly a good sound

That's very honest of you to say so, Alan, and I completely concur with your summary of what was heard at MiBO

As I said before, the Lentek also gives my £1500 Paul Hynes head amp/off-board linear PSU a hard time, and that, like your FB 2000, is a superb sounding piece of kit. I think you'll agree that, also like you, I know a good sound when I hear it. Furthermore, I'm not using one because I can't afford anything else better either!

So there's a bloody good reason why the Lentek is discussed here so often....... Fact is, it *deserves* it

Marco.

[Arkless Electronics]

It's popular because it sounds bloody good, and it's cheap!

Perhaps at the next NEBO you could bring one of your head amps along and test it against the Lentek and I (along with others present) give you our honest opinion?



Nothing wrong with the former - it's called 'supply the demand', although the demand in this instance is small. However, head amps/SUTs and such devices are discussed on AoS than on any other forum I know, so if you're going to sell any, it'll be here...

In terms of the last bit, you've got the concept all wrong, and I've been meaning to mention this to you for a while. With these types of bespoke products it's completely unrealistic, mate, to expect people just to automatically buy whatever it is you're offering, without first listening to it themselves.

Therefore, if you're offering to copy the Lentek circuit, then if you want sales, you'll have to MAKE ONE FIRST (as demo unit), then send it out to people interested, just as Alan (Firebottle) has done with his stuff, and let the users themselves decide if its any good or not, or indeed as good as an actual Lentek.

I've not doubt that it would be, but you have to put the product out there first, and allow it to be assessed, before any likelihood of sales will happen. That's just how it works, hence my reference earlier to 'speculate to accumulate'. If you're not willing to do that, then I completely understand, but it's the *only* way you'll generate sales for such items.

However, if you could get the circuit from already published photos, and publish it here for reference, then that would be a nice thing to do for the AoS community, and a way of showing thanks for the support your business has been given, especially in hard times before you came here (think what happened on pfm)

Marco.

Ahem... It was I who was doing this first! (and using loading plugs for cartridge matching while I'm at it... not that I was the first)

As far as doing the lentek thing as a thankyou etc well that's what the DIY pre amp was about, as I said in the thread, which I spent probably 30 hours work on and it had no interest so that's a no. The photos on the web I was thinking about, which showed probably enough to work out the circuit, seem to no longer exist so it's academic any way. As I would have been copying a unit that's already popular I can't see why "try before buy" would be necessary.

I would indeed be making them to order only, as with virtually everything I can make. Remember, I have no money. I can't afford to build stuff first and then see if anyone wants to buy it.... Obviously I will be making a hybrid full function pre amp for demo as that is something I consider a "stock product". In the case of the hybrid pre amp though there will be almost unlimited options and upgrades available... which yep.. you guessed it... one will not be able to try before buying when it comes to the options and upgrades... simply not possible! Can you imagine? "I want to try one with the switched attenuator vol control, the bulk foil resistors, twin tape loops and some boutique caps in the phono stage".... yeah I'll just knock one up to that spec at a cost of £800 in parts and 2 weeks labour just so you can hear it and THEN decide whether or not to buy it.... it ain't going to happen.
It occurred to me even when I first mooted the idea that I may have to kill all the upgrade options at birth just to avoid offering so many possibilities that people can't make their mind up... or that all the upgrade options may put some off cos some think that the standard one must be nowt special... No good deed goes unpunished etc!

The one for demo BTW will be a full function pre amp (ie with phono stage and active as well as passive line stage) built to "bog stock" spec other than probably some Mullard NOS valves in it. If someone is interested in just a phono stage then they borrow the full function unit and use it as just a phono stage by feeding the "Tape Out" signal to their own pre amp. If wanting just a line stage then try it but don't connect a TT to the "Phono" input. Simples.

[Arkless Electronics]

Here are some notes I made when I was repairing Steve's
I should have sketched it out at the time
Note i dont know what the NPN transistors are as there is no markings
From the front view L to R E-C-B


LENTEK HEAD A MP by Alan Towell, on Flickr

Pic of the underside

IMG_2683 by Alan Towell, on Flickr

Alan

Now that makes it doable but a photo from the top with a light underneath would make it much easier...

[337alant]

I think you could do a good little MC head amp with a single op amp for each channel

Alan

[Arkless Electronics]

Marco took his to MiBO so I got to hear for the first time what the appeal is about the Lentek. I swapped my Firebottle 2000 head amp in directly afterwards as a comparison (who wouldn't ) and it was a very interesting comparison. Not a huge difference as I may have been expecting.

I thought the FB 2000 gave a 'smoother' presentation but the Lentek majored on boogie factor and musicality. Difficult to quantify 'musicality' but certainly a good sound

As good as it may well sound, all those caps in the signal path, in a head amp, will be by far the biggest issue holding it back... or adding some colouration that is interpreted as "boogie factor" and "musicality", both IMHO of course

[Arkless Electronics]

I think you could do a good little MC head amp with a single op amp for each channel

Alan

Easily doable but I reckon it would not sound anything that special. The Arkless 640P kind of works like this and it allows me to offer MM and MC on this without the usual compromises being such a big problem. However, although the Arkless 640P sounds great and is excellent VFM, it is a fairly budget product and I reckon using similar technology in a head amp to place before a £1000+ MM stage would likely hold back the overall performance...

[337alant]

Now that makes it doable but a photo from the top with a light underneath would make it much easier...

Can't do now Jez unfortunately
Alan