LENCO - GL75 Project

[brian2957]

Brian, both relieved and very pleased for you that the Gimp has worked. I always assumed the Gimp worked but just like you I do have a slight suspicion that the mats have slightly altered the tonearm alignment. Personally, just like you I don't care. So great minds and all that.

Thinking about it , there's a strong possibility that the Gimp mat is also providing an extra layer of isolation from the vibrations of the motor . However , I have no way of proving this Andy .

[Gazjam]

Thinking about it , there's a strong possibility that the Gimp mat is also providing an extra layer of isolation from the vibrations of the motor . However , I have no way of proving this Andy .

What's this "gimp mat" you speak of...?

[brian2957]

I'll pay you a visit and show you mate https://www.amazon.co.uk/Fonotek-TUR...ds=fonotek+mat

[struth]

gimp as in limp or floppy I guess.

[brian2957]

Hah ! that's more like it Grant

[Wakefield Turntables]

Nice write up again Andy . It looks like another success story with an upgrade for the GL75 . The options for upgrading are getting scarce now mate . How does it now compare to your other turntables ?
This thread will be a fantastic resource should funds allow me to go down the same path in the future . For now I'm just enjoying the music

I still think we have quite some way to go. Mainly

1. Experiments in decoupling - the bearing and tonearm.
2. Xperiments in coupling - the top plate to the plinth
3. Experiments in vibration control - mainly absorption, dissipation, altering characteristics
4. Possibly more component optimisation
5. Cartridges

I'd probably go for vibration control and dampening as the next set of tweeks, they are cheap, cheerful and easily removed. Xmas is coming and funds for a new bearing will have to wait until 2017. Each of my decks does different things for different music. For example the 301 just "does" jazz far better than either my 301 or '75. The 1210 excels at intricate prog, heavy metal, classic rock, synth based music. The Lenco sits solidly in the middle it's an extremely good all rounder in that it's gives the 301 and 1210 a good run for their money but dosen't better them. I could quite happily live this deck if I didn't own the others.

[Wakefield Turntables]

Not much doing tonight here in Wakefield. I've had the NSC down to 210V and did not like what I heard. It seems to be correct that lower volt values seem to screw up the soundstage and things go all mushy I could hear quite severe degradation of the piano in Kind of Blue (Miles Davis) tonight you could almost hear the soundstage firming up as you dialled the voltage back upto 220V. I remember asking about optimum voltage values for the 301 and most people seemed to suggest the 215-225V range so it looks like this might (to my ears) be a similar phenomen on the '75. The experimentation continues.

[brian2957]

Good feedback Andrew . Are you going to go the other way and try increasing the voltage to over 220V ?

[Wakefield Turntables]

Nice write up again Andy . It looks like another success story with an upgrade for the GL75 . The options for upgrading are getting scarce now mate . How does it now compare to your other turntables ?
This thread will be a fantastic resource should funds allow me to go down the same path in the future . For now I'm just enjoying the music

Good feedback Andrew . Are you going to go the other way and try increasing the voltage to over 220V ?

well both my 301 &1210 run at 240v so I can't see why we can't experiment and the '75 was running straight from the mains which is usually 245v into our house.

[helma]

Not much doing tonight here in Wakefield. I've had the NSC down to 210V and did not like what I heard. It seems to be correct that lower volt values seem to screw up the soundstage and things go all mushy I could hear quite severe degradation of the piano in Kind of Blue (Miles Davis) tonight you could almost hear the soundstage firming up as you dialled the voltage back upto 220V. I remember asking about optimum voltage values for the 301 and most people seemed to suggest the 215-225V range so it looks like this might (to my ears) be a similar phenomen on the '75. The experimentation continues.

That does make sense, after all 220V was the mains voltage at least the Lenco was designed for. I don't think these motors are all that sensitive to voltage variations, but somewhere there is a spot or range where you get the best compromise between vibration / torque. Did you check speed and make adjustments if necessary when experimenting with the voltages? I'm not sure how exactly the Lenco motor works, but I don't think it's straight induction motor because if I recall correctly it was quite insensitive to voltage variations + it gets up to speed and mostly speed stable pretty quickly. I don't think it's synchronous either, I think there's a motor design that is sort of semi-synchronous, kind of like a step between the two types, it probably has a fancy name? The motor in Dual 1019 is a straight induction motor, and it was a lot more sensitive to changing the voltage and it also take a good half hour or so to warmp up and reach final speed, the speed gets slowly faster and faster as the motor warms up to operating temperature. I think it was probably Garrard who came up with a way to modify an induction motor to be less sensitive to voltage variations and behave more like a synchronous motor, while still retaining the better torque / size ratio of induction motors.

On completely different note, personally I'd get rid of that Shure before anything else, but if it's a cartridge you know and like, then maybe you're good on that front I just don't like the vintage Shures myself, at least most of them, though I have to admit I haven't heard the M55 but if it's anything at all like M75 I know I'd hate it. Also the bass lightness you mentioned, I suppose it depends on how light exactly it is, but I don't think it should be a feature of the Lenco, I'd suspect arm and/or cartridge first. I know most people wouldn't call the vintage Shures exactly bass light, but IME they don't really do deep bass that well, despite having a somewhat pronounced mid bass.