LENCO - GL75 Project

[brian2957]

Nice write-up again Andy . The only things I have done to my GL75 so far have been :

Stripped the bearing and fitted PEEK thrust pad and ceramic bearing . Lubricated with Lithium grease .

Fitted bearing collar .

Fitted new V-blocks to the tonearm .

Fitted a Shure M55E and basic Jico stylus .

Replaced the idler wheel and shaft ( there was a slight kink in the original shaft and the six hole idler wheel seems more substantial than the two hole one )

Fitted a little locking collar to the idler wheel which has removed a small amount of wobble .

Fitted large oak cones to the bottom of the turntable .

All these little tweeks have improved the turntable incrementally .

I take it the crystal mat is an improvement over the original one .
I'm trying to keep this GL75 as original as possible , however , when funds allow I will probably buy another one and follow the route you have taken with yours .
Good work Andy

[Jimbo]

Nice write-up again Andy . The only things I have done to my GL75 so far have been :

Stripped the bearing and fitted PEEK thrust pad and ceramic bearing . Lubricated with Lithium grease .

Fitted bearing collar .

Fitted new V-blocks to the tonearm .

Fitted a Shure M55E and basic Jico stylus .

Replaced the idler wheel and shaft ( there was a slight kink in the original shaft and the six hole idler wheel seems more substantial than the two hole one )

Fitted a little locking collar to the idler wheel which has removed a small amount of wobble .

Fitted large oak cones to the bottom of the turntable .

All these little tweeks have improved the turntable incrementally .

I take it the crystal mat is an improvement over the original one .
I'm trying to keep this GL75 as original as possible , however , when funds allow I will probably buy another one and follow the route you have taken with yours .
Good work Andy

Hi Brian,

Playing much vinyl?

[brian2957]

Was away last week James , came back on Sunday and was quite surprised at how good the GL75 was sounding . So yes mate . Most of Sunday and a fair bit Monday and Tuesday

Unfortunately I've got to sleep sometimes

[Wakefield Turntables]

Brian,
Just a word of warning re the crystal mat. It's 6mm thick so you might have to play around with the Lencos tone arm pillar to heighten the tone arm to accommodate the extra thickness. Also re check cartridge tracking weight and that's it's parallel to the vinyl, mine got buggered up when I started using it on the Lenco. Secondly I would counsel that you "learn" the sound of your Lenco intimately and then that way you can discern where the crystal mat has improved things. It took me ages to recognise the effects on the soundstage when I first started using them.

[brian2957]

Thanks Andy , I'll have to investigate further before spending any more on this mat .

[Wakefield Turntables]

Tonights update - Idle thoughts!

Platter Mats Pt 4 - Or special Brian edition - Definite last thoughts on Lenco platter mats!

I spoke to my old mate Brian today and chewed the fat a bit with regards platter mats. Brian wants to keep his Lenco stock and TBH I love that idea. I do think that the stock deck can be improved marginally with the addition of a second platter mat under the original Lenco offering. So, I advised Brian to either look for a cork mat or possibly the unfortunately names "Gimp" mat from eBay

My current platter mat setup until the new Crystal mat arrives. The Garrard 301 + Gimp mat, I'm currently listening to this and can't believe how good these two mats sound.

.DSCN2729.jpg

The Gimp mat, £15 from eBay.

DSCN2728.jpg

Of course you might want to try Cork under the Lenco mat I've heard that this produces pretty good results but unfortunately haven't had chance to assess. The gimp mat adds an additional 2mm height so VTA, and tracking forces would need to be checked but TBH I dont think it would make that much difference.

Thoughts on the Idler Arm pt 1

More discussion with Brian got me round to thinking about the Idler arm and also vibration supression into the bearing, and idler arm break and indeed the idler wheel. So, I went into the cellar at work and fetch home some offcuts to play around with. So we have some EVA, Sorbothane or Eurethane. The idea is to make some washers using the various materials to act as dampeners.

DSCN2720.jpg

This picture shows the underside of my deck. The break has now been removed. I was thinking about getting some new longer screws for the bearing alongside some washers and additional for the idler arm break. My thoughts are to add additional Sorbothane or EVA washer under the screw and then tighten the nuts, the logic is simple. Sorbothane works by supressing vibration whilst being loaded with a vertial weight. The nut and washer will be added the vertical load so should supression vibration getting into the three screws that hold the bearing. The idler arm break will also recieve the same treatment but I'll cut a small piece of Sorbothane to match the surface area of the break and then attach this to the top plate with a new long screw and then add a sorbothane on the underside of the top plate and tighten. This should help vibration getting into the idler arm. I also think that the speed adjustment slider, and idler parking arm could also benefit from vibration supression. It's kind of hard to detail what I mean so I guess I need to post some pictures at some point.

DSCN2721.jpg


I decided to have a look at my idler wheel today to check for oscillation and I'm buggered to report that my idler wheel does indeed have a small amount of oscillation. I did have a video prepared but unfortunately it was too big to attach to this post. Brian has pointed out that a fix does exist and it has now been ordered I will post pictures when said fix has been applied. I will not be dampening the idler arm with PTFE tape as now evidence exists to prove it's efficacy. I will not be buying a replacement titanium idler arm or adding a stut across the the top of idler arm again no efficacy exists and I additionally believe that stiffening the idler arm too much may actually have an effect of pulling the idler wheel away from the true position on the motor spindle to achieve 33.3 rpm (just my own thoughts).


These little thoughts and tweeks have gone down on my list of stuff to do bewteen now and Xmas. The speed controller should be with me soon so I'll probably start talking about that. I will then start to implement some of these tweeks and then once I've gained a better understanding of how the speed controller is affecting the '75 can comment further on if any of this waffle has been beneficial or a red herring.

OK, bugger off you lot (meant in the nicest possible way).

[Wakefield Turntables]

Mats Pt IV - The very last ever ever post here guv'nor. Honest.

Well whilst waiting for the speed controller I thought I'd compare the Crystal mat with the Garrard / Gimp mat setup, and............. the Garrard/Gimp setup wins. There is just something about this combo which sounds correct. The Crystal mat does indeed bring out more detail but overall I have to go with my heart and ears and I have to say that I do not like the Crystal mat on the '75. So, I've saved myself £70 and not bought another Crystal mat. I don't know why but glass / aluminium / copper seems to sound better on DD decks compared to my Idler's. This has now happened with my 301 and '75. The Speed controller is now in Wakefield (I hope) so it'll get picked up tonight and then it's on with the Speed controller experiments. The idler arm will probably get some attention in November and then it should be fun decoupling the bearing from the top plate in December.

[brian2957]

Just saw this Andy as I've been nightshift and sleeping for most of the day . Again , another informative write-up on your experiments with the GL75 . I have ordered the '' unfortunately named '' Gimp mat to try with the original GL75 mat . Did you say Gimp mat top or bottom mate ? It's really interesting how these mats interact with these turntables .
As I want to keep the GL75 as stock as possible , I'm not sure about removing parts , even if they aren't getting used . So I may just put some kind of vibration suppression in there .
Good move getting the little clamp for the idler wheel . It also comes with two little Teflon washers and is indeed an effective way of removing any play . I'll be watching with interest on how the speed controller affects the performance of the GL75 .
Thanks again Andy for sharing your thoughts on these modifications in such detail

[Wakefield Turntables]

Plonk your gimp under your Lenco mat. It might be worthwhile looking for an old radiogram, maybe in the charity shops or free ads locally to possibly source a mat similar to the Garrard, that is if you fancy trying out more mat combo's. I've got a cork mat but I honestly can't be bothered with more mat experiments they are both costly on sanity, time and listening to vinyl. I've been looking closely at decoupling the bearing I think that this could be probably one of the best free tweaks that's possible on these idlers. There is an article here http://www.lencoheaven.net/forum/index.php?topic=5186.0 which might be of some benefit. I'm now about 75% through reading all the theads on Lenco Heaven and the components forum is the one where I feel I'm going to get more clues to get more out of this deck.

[brian2957]

Thanks Andy , that's a plan then regarding the mats . I'll have to keep my eye open for any other mats on old gear to try . The thread you linked to on Lenco Heaven looks very interesting and will be my reading for the nightshift tonight .
Last night I discovered that the suspension springs had to go on a certain way and that they are different sizes so the GL75 will be getting taken to bits again