Rebuilding and modifying my Lentek head amp

[DarrenHW]

It looks so pretty now Anthony's finished with it!

I did look into modding the Lentek, but from the point of view of the power supply i.e. the Battery. If I am to keep the Lentek I'd make it external, not that I expect any audible benefit from doing this, but it would make the process of changing the battery a lot more user friendly! This would then give the option to run multiple 9v batteries in parallel or better still a smart rechargeable 9v pack, which I would hope would offer an audible benefit due to the increased amperage, but even if it didn't it would mean extended battery life and a means to test battery power.

[RobsterD]

I tried changing the battery for an external regulated PSU all I got was hum dunno why so reverted back to battery

[Marco]

Marco, I'm glad your enjoying yourself again. It's nice to see you post on a regular basis. I decided against toying around with head amps. I didn't really see the need for another box in the signal path. I must admit to still using a SUT with my Cadenza Black on the 1210. I'm afraid I'm enjoying vintage MM's + valve phonostages to worry too much about head amps. I never really gelled with the 103 and I've owed the 103R, 103M and the 103 stock. I'll not be visiting the 103 stable. I'm having way too much fun with the SC35C and EAR834P combo.

Fair enough, Andy, and thanks. My hiatus from 'hi-fi shenanigans' was only liable to be fairly short lived, as my passion for it has always remained. It was simply that I was more involved with my other interests and hobbies, especially when life was more normal and the weather was good. However, with the lockdown situation and now the winter months arriving, my interest in hi-fi has been rekindled!

In terms of what you've said about the 103, can I ask if you've ever used it in a high-mass arm, say a typical Jap one with a detachable headshell, such as I use, or the likes of an FR64, or just on your usual, is it, SME V? If not, then that would ably explain why you've never got on with it, as quite simply it won't work properly on that kind of arm.

For a 103 to sound right, the headshell alone has to be (min) 16g. It also sounds much better when used through an MM phono stage, together with either a head amp or an SUT, than through a standalone MC stage, hence why I've put so much effort into optimising the performance of those types of devices I use with it, the Lentek being a case in point.

However, I'm glad you're enjoying the SC35C, with your EAR, which I'm sure sounds fab. As you know, I'm a big fan of that cartridge, again when optimally set up and partnered - and IME it's as fussy in that respect as a 103! How did you get on with the NOS stylus you bought, and have you added any further capacitance, by experimenting with loading?

Marco.

[Marco]

Hi Rob,

Hi Marco
Good job !but isn’t it cheating not doing it yourself
I did something similar though interesting re the chalcrofts might investigate that.
I did Kiwame resistors ,Nichicon and Wima caps with CMC phonos and
Audio Origami output lead bested a Puresound T10

Lol - I guess it is cheating,, but I wanted the thread eventually to archive on a part of the forum where it'd be most relevant to those interested in the topic

Interesting that yours bested a T10, which in itself is a nice bit of kit and considerably more expensive than the Lentek, even when modded.

I'm not a big fan of Kiwames though, finding them a bit warm sounding for my tastes (good for 'taming' some digital circuits, though), and with the Lentek. given what I've learned now, I'd always retain the Tants. Wimas in any other circuit would almost certainly be better, but for me the Tants are a big part of what gives the Lentek its 'proper' sound

Marco.

[Marco]

Aye , excellent work . Good to see you getting into modding again Marco . Your posts in this area are always detailed and interesting

Hi Brian,

Cheers, mate. As you know, Anthony's top notch, plus him and I generally agree on where to take projects like this, sonically, so he's easy to work with, and of course also a good friend

I always try to make these types of threads as interesting and informative as possible, as indeed I did with the Techy threads, while I was going through my journey of modding it, or indeed with anything else I've done similar things to. For me, it only works right if you focus on the details, and do things as methodically and correctly as possible, rather than rushing things through impatience

Marco.

[Wakefield Turntables]

Fair enough, Andy, and thanks. My hiatus from 'hi-fi shenanigans' was only liable to be fairly short lived, as my passion for it has always remained. It was simply that I was more involved with my other interests and hobbies, especially when life was more normal and the weather was good. However, with the lockdown situation and now the winter months arriving, my interest in hi-fi has been rekindled!

In terms of what you've said about the 103, can I ask if you've ever used it in a high-mass arm, say a typical Jap one with a detachable headshell, such as I use, or the likes of an FR64, or just on your usual, is it, SME V? If not, then that would ably explain why you've never got on with it, as quite simply it won't work properly on that kind of arm.

For a 103 to sound right, the headshell alone has to be (min) 16g. It also sounds much better when used through an MM phono stage, together with either a head amp or an SUT, than through a standalone MC stage, hence why I've put so much effort into optimising the performance of those types of devices I use with it, the Lentek being a case in point.

However, I'm glad you're enjoying the SC35C, with your EAR, which I'm sure sounds fab. As you know, I'm a big fan of that cartridge, again when optimally set up and partnered - and IME it's as fussy in that respect as a 103! How did you get on with the NOS stylus you bought, and have you added any further capacitance, by experimenting with loading?

Marco.

I've not done the high mass arm route and I really must start trying Jap stuff. Life's moving on and it's one of those areas that I keep promising myself that I must visit. I'm still on the SME V and now also a V-12 I have been tempted to try the FR64 but just never got around to purchasing one. The 103 did sound reasonable on my SME 3012 but I strongly suspect that I hadn't properly optimised it.

Now the SC35C is a different kettle of fish and as such I have optimised things further still. My capacitiance loading experiments are over as I feel I have reached optimum loading. The NOS stylus hasn't been out of the packet yet. I'm having far too much fun with the JICO SAS/s version which I strongly recommend. I have been experimenting in two other areas. Firstly with power supplies to the 301 and also with an Oscilloscope for improving stereo channel separation. I use a Phoenix Engineering PSU + Tachometer to control the 301 speed, it's a great product let down by lousy power SMPS supplies that introduce a lot of noise into the equation. This has driven my crazy over the last 3 months. I've now removed the SMPS products for the 9V battery supply and cheap linear regulated PSU from China. Now I have no hum and the soundstage is quite and both massive and glorious. The Oscilloscope is still a learning curve but does improve stereo channel separation. So, my next area's of experimentation and investment are going to be super low noise PSU's and a better valve phonostage.

[Marco]

It looks so pretty now Anthony's finished with it!

Lol - cheers, mate. He's a very neat worker

I did look into modding the Lentek, but from the point of view of the power supply i.e. the Battery. If I am to keep the Lentek I'd make it external, not that I expect any audible benefit from doing this, but it would make the process of changing the battery a lot more user friendly! This would then give the option to run multiple 9v batteries in parallel or better still a smart rechargeable 9v pack, which I would hope would offer an audible benefit due to the increased amperage, but even if it didn't it would mean extended battery life and a means to test battery power.

Yup, makes sense, so if/when you go ahead with that project, I'd be interested in hearing the results. I'd defo keep the Lentek though, as long as you're retaining the services of your 103, as it's such a sonically synergistic partnership.

Marco.

[Marco]

I tried changing the battery for an external regulated PSU all I got was hum dunno why so reverted back to battery

I think one of the reasons why the Lentek sounds good is because of the lack of mains-borne noise/interference, when amplifying such a delicate low-level signal. Battery power in that particular application therefore, for me, is the way to go

Marco.

[Marco]

I've not done the high mass arm route and I really must start trying Jap stuff. Life's moving on and it's one of those areas that I keep promising myself that I must visit. I'm still on the SME V and now also a V-12 I have been tempted to try the FR64 but just never got around to purchasing one. The 103 did sound reasonable on my SME 3012 but I strongly suspect that I hadn't properly optimised it.

Yup, as do I... Given that you love the sound of the SC35C, I think you'd be equally enamoured by a fully-optimised 103, as both have similar traits

Now the SC35C is a different kettle of fish and as such I have optimised things further still. My capacitiance loading experiments are over as I feel I have reached optimum loading. The NOS stylus hasn't been out of the packet yet. I'm having far too much fun with the JICO SAS/s version which I strongly recommend. I have been experimenting in two other areas. Firstly with power supplies to the 301 and also with an Oscilloscope for improving stereo channel separation. I use a Phoenix Engineering PSU + Tachometer to control the 301 speed, it's a great product let down by lousy power SMPS supplies that introduce a lot of noise into the equation. This has driven my crazy over the last 3 months. I've now removed the SMPS products for the 9V battery supply and cheap linear regulated PSU from China. Now I have no hum and the soundstage is quite and both massive and glorious. The Oscilloscope is still a learning curve but does improve stereo channel separation. So, my next area's of experimentation and investment are going to be super low noise PSU's and a better valve phonostage.

Interesting stuff... I've no doubt that you've improved matters in that area, as I'm no fan of noisy SMPS units, used in any audio application. Also, I've always preferred the 301 to a 401, and considered that if the former was properly fettled, it'd not be the latter's inferior brother - and also IMO is the better looking!

There are two idler T/Ts I'd love to own quality examples of, and that's a TD-124 and 301. In terms of the latter, I'd like an Audio Grail 'hammered grey' BBC one, and may well add one to my system at some point in future

Marco.

[Frinpaul]

Hi Marco,

Thanks for such a prompt and detailed reply - much appreciated!

I take your point about the original output cables being a potential bottleneck; I have thought that might well be the case, especially as one of the phono connectors on mine is slightly temperamental. Is it relatively straightforward to change the cables and, if so, could you recommend cables that would be an improvement? I'm afraid any internal work on the Lentek would likely be beyond me - actually, it was the fact that you mentioned that you had outsourced the work that initially piqued my interest.

I agree that Duracells seem to be about the best match battery-wise. I was, though, very impressed with some Philips alkalines that I tried a few years ago - they were being sold in Poundland, and were the only batteries I've tried that I felt were (at least) a sonic match for the Duracells in the Lentek.

All the best