401 birch or slate?

Panzerholz? Looks like a lot of hassle.

Panzerholz? Looks like a lot of hassle.

Depends if your going to buy it or fabricate it yourself.

Its usually found in a specific layer as opposed to a multiple stacked
construction.

Looks like I'll have to import a slate plinth from the UK. Not much interest on this side of the pond and PA-based Oswald Mills start at a ludicrous $5000. 

@noromance
From personal experience the SMD Quartz plinths built in the UK are very good. However, since you appear to have a reasonable plinth already, I would suggest you consider doing the following -

• Large platter & bearing from Classic Turntables - this improved the timing and coherence from the 401 substantially.
  
• Idler wheel from Artisan Fidelity - this added a significant level of refinement, particularly in the high end
  
• Power Supply from Classic Turntables - significant increase in resolution and high frequency purity
  

These mods I heard in a system I know well and can highly recommend. They took a fully refurbished and blueprinted 401 to another level by a considerable margin.

Thanks @dover . This is very good stuff. I’ll look into the AF idler wheel for my birthday! Looks like I will go with slate. I have found a source in the US.
Not sure if I should open a new post but...If using slate, should I use an arm-board or mount on the plinth?

I went with slate. See my Virtual Systems entry for update.

@dover  You said "Idler wheel from Artisan Fidelity - this added a significant level of refinement, particularly in the high end"

Could you kindly elaborate in a bit more detail what you mean? I'm tempted to get this wheel. I notice there is another offering from Audiosilente in Italy for 1/4 of the price. Thanks.

@noromance 
I would describe the improvement of the AF idler wheel as similar to a cartridge upgrade - the higher frequencies were more detailed, more nuanced. There were also improvements in coherency and musical timing.
When we upgraded to the Artisan Fidelity idler wheel, the 401 had already been refurbished by Audio Grail, in other words the AF idler replaced a refurbished standard idler wheel in good condition. The 401 in question also had had an upgraded platter and bearing from Peak Audio which had yielded a massive ( not hyperbole ) improvement in musical timing.
 

Thank you. Was it difficult to fit? Do you use the original bushes? As you know, my new 401 is also an AG version. Early flat window, twin spark.

@noromance 
Drop in replacement. Undo 2 screws holding the top of the idler, lift out the idler wheel and drop in the replacement - literally 2 minute job. Drop a little oil on the spindle ( top and bottom ) to avoid any scouring. The bushes in the 401 were in good shape.

As an aside I have a 301 rebuild on the go and the new sintered bushes from Audio Silente look very good. I have purchased both motor bushes and idler bushes but have not installed these yet. Their idler is a good price but not in the same league as the AF.

@dover Spoke to Matthew at AG who recommended the AS version so I ordered one for the AG/slate 401. If it makes an improvement, I’ll consider the AF one and move the AS version to my birch-ply 401. Thanks and good luck with the 301.

@dover Revisiting this thread. I ended up acting on your advice shortly after these posts. Initially went with the AS idler and then got the AF one. Improvements above as noted. 

@dover Also replaced platter and bearing which have transformed the table. This is NOT your dad's old Garrard in a ply box!

@noromance 
Hi there,
Good to hear about your upgrades. Great looking 401 with the slate plinth.

Since my last post I have rebuilt my listening buddies AG 401 with a custom engineered quartz stone plinth, 12kg brass platter & bearing, and Kuzma 4Point11. Cartridges are Kuzma CAR50 and Van Den Hul Calibri. The Kuzma replaced a Moerch DP8 & Helius Omega. It's an excellent arm and works with the 401 beautifully.

So yeah - I have a good idea of what you've got.

I think the 401's are a bargain as far as high end tables go and there are plenty of off the shelf upgrades.

@noromance 
Should also tell you I built a 301 for a spare TT for myself and to run 78's. It blitzed my old second deck which was a Platine Verdier.

Some of my mods included -

Full motor rebuild, new bushes, blueprinted evrything internally - only runs half as hot as original and very quiet.
I replaced all the rivets connecting the linkages under the chassis with nylon bushes/teflon washers & nautical grease to eliminate most of the metal to metal contact under the chassis.
Separated the motor on/off switch from the on/off lever so that when you change records the idler wheel disengages but the motor remains running - this is a big advantage because the motor takes a while to stabilise each time you turn it off and on. It also removes 230V from under the cartridge.
Reworked the bearing and platter.
Custom built a high density compressed fiber bamboo plinth.
Replaced the rubber inserts under the chassis with carbon fibre washers. 301 is through bolted to the bamboo plinth with carbon fibre washers above and below.

There are a few other tweaks as well.

Currently running Fidelity FR64S/B60 with various cartridges on that deck. A few of my friends have been shocked by the performance capability of the old Garrard.

FWIW the 401 is a better deck for modding, it has a stronger motor - the 301 is more rube goldberg.

the 301 is more rube goldberg.

And to think what the prototype was like displayed at an early exposition and looking nothing like the final version.

fun thread…i have my long range eye on 9” Kuzma as it will fit my SOTA

i need to stumble on a 401 garage sale find……probably like hoping for a barn 356….. ha.

the 301 is more rube goldberg.

So much so a family member threw one away thinking it was some old junk.

@tomic601 A man of your means and sonic acumen should truly consider a refurbished one. 

@dover Love hearing about your endeavors. The brass kit looks serious along with the price. Shaun D. at Peak HiFi told me the brass lends a warmer and more organic sound. I'm happy with the aluminium but would like to try the stainless steel. 

I have a virgin AG 401 flat strobe in a box and not sure what I want to do with it. Use it upstairs in a small plinth with a 9" arm for background music, or build another 12" and load it up with the good stuff. What type of plinth? Panzer, bamboo, quartz, slate, open skeletal etc?

Awesome table noromance!

@boxer12  Thanks!

It will be interesting to try the slightly bigger and heavier PAC platter that's on order over the SMD one on it currently.
PAC - 317mm +900grams
SMD - 304mm +420 grams

This thread has drifted from plinth choices to general modifications. I have replied to many of these types of threads in the past. See my profile. While slate plinths sure look nice and appeal to the brain's common sense notion that high mass must be better, t'aint necessarily so with the 301/401. I have not heard them all but have heard many. I went with layers of birch built by Russ Collinson. Most Garrard experts will tell you that a sizable birch or similar wood plinth gives the best balance of warmth, isolation, and dynamics. 
As I have also commented upon elsewhere, I have three platters for my heavily modded 301, the original, a Classic HiFi solid brass (30 lbs or so) and the Steve Dobbins platter (~8 lbs). The Dobbins platter has a copper top on alloy. I like the Dobbins best. All have their virtues. Liveliness/excitement-original platter. Refinement-the heavy solid brass. Mix of both-the Dobbins. 
I use the Classic HiFi PSU, a 10.5 Reed 3P, and my present cartridge is a Lyra Etna Lambda. I have Stillpointe SS footers. I use a Roadrunner to keep track of speed. Brian Walsh does my set-ups. He confirms my sound is right up there. I don't for an instant claim my 301 is better than anyone else's. But it sure makes me happy. 

@fsonicsmith Thanks for your comment. I have both a layered birch ply with 1/2" walnut top plinth and a 50mm Pennsylvania slate plinth. I like both but the slate is better on the retrieval of the finest detail.