Musicmaster Model 12 (Gray clone) Tip + GE VRII Hack

Canon P + Canon 50mm f1.8 
Foma 100 in Rodinal 1+50

After many decades of collecting and using classic audio equipment and film cameras, I've learned to accept that sometimes I win, sometimes I lose, but most of the time I break even. And the only reason there is that possibility of breaking even is because I learned to DIY.

This tonearm came with a KS Musicmaster Model 25B12GST idler-driven turntable, which I thought I could resuscitate. Alas, the turntable was beyond saving because a lot of important parts were missing. The tonearm had no head shell slide and the cartridge pin contact points + wiring harness were gone. For many years this tonearm was boxed up along with other parts units sitting in storage.

One day I had an epiphany - will the Karmadon head shell slide fit? 

 I'm happy to report that the two types of head shell slides that my buddy, Sergiy, manufactures for his Gray Research tonearm clone work on this Japanese clone as well as on my original Gray Research 108C. Above left is a solid shell and on the right is a shell with a hole to accommodate the triple play feature of the General Electric RPX and VRII mono cartridges. 

Despite the carnage brought upon the Ukrainians by a deranged autocrat, my Karmadon head shells arrived in less than two weeks. We really have to admire and support these people!

I rewired the tonearm and blu-tacked 4 pennies to make up for the lost hardware.

A blob of 600,000 cSt silicone fluid was injected into the uni-pivot bearing cup.

Since the Karmadon head shell slide is lighter than the original, I used all three copper weights Sergiy provided, added 2 x 5 centavo coins + the GE VRII cartridge = 25 grams. 

I misplaced my VRII cartridge pins 😞...but after a bit of head scratching, I hacked two tube pins from a dead octal based tube and soldered them to the signal wires.😊

Voila!👍

For more viscous damped tonearm set up information, please click here!

 Even with my 20+ years of experience using this tonearm, it took me a while to dial-in the proper weight compensation due to the missing hardware + adapted head shell slide. Getting a viscous damped tonearm to function properly isn't for the faint of heart and requires patience. If you don't possess these virtues, I suggest you don't consider using one. But I must say the results are well worth it!😊

Musicmaster Model 12 + GE VRII

Let's listen to a few monaural hifi tunes!

🎶🎻🎹🎷

VAS Audio: SPU GME II and Supex SD900 IV retip + Stax UA-3NL and Tokyo Sound ST900 repair

 

VAS Audio Workshop

Before lockdown, Ding promised that he'd introduce me to his friend, Steve Leung, of VAS Audio. He's had his Denon DL103S, Ortofon SL15, Supex SD900, and other classic cartridges re-tipped and repaired by Steve. As the pandemic wound down, I finally got to meet Steve and brought the following MC cartridges for new tips, as well as tonearms for repair at his shop.

Ortofon SPU GME MKII

SPU GME MKII - BEFORE

My Ortofon SPU GME MKII has had a hard life ever since it was gifted to me by my SETUP buddies in the 90s. It's been on semi-retirement since I acquired an SPU#1s + a late 60s or 70s(?) SPU-G (below) with a low mileage nude mounted conical stylus.

SPU-G

This SPU-G portrays a wider and airier sonic landscape with perhaps a bit more detail compared to my more recent SPU#1s. It also sounds more organic than the GME MKII. 

SPU GM(E) MKII - AFTER

I attribute the SPU-G's sonic superiority to the better polished nude mounted conical stylus vs. the bonded conical stylus of the SPU#1s. So I asked Steve to fit his finest nude mounted conical stylus on my GME MKII.  

Ortofon SPU GM(E) MKII

Agreeing to my downgrade idea,😉 Steve may have turned the GME MKII into an SPU-G equivalent of the SPU-A wood. All I know is, it can stand up to my cousin's SPU Synergy!😊

Supex SD900 MKIV

BEFORE

The Koetsu Black and Supex SD900 were my dream cartridges back in the 80s. When I finally found an SD900 I could afford, it sported a ruby cantilever + complex stylus profile upgrade.😏 Although traces of the classic Supex tonality were still there, it sounded compressed and swamped by dry analytical detail.😞

AFTER

I asked Steve to work the same magic on my Supex as he did on Ding's, albeit with a twist. We agreed upon an aluminum cantilever just like the original and I requested for another nude mounted spherical stylus.

SD900 MK IVs (s = spherical)

Steve remarkably transformed the Supex! The harmonic richness and dynamics this classic MC cartridge is known for was restored. To my ears, the SD900's edge over my SPUs and DL103s is its ability to focus and retrieve detail without inducing tinnitus. Because of Steve's phenomenal restomod job, I'm no longer yearning for a Koetsu! 😊

Stax UA-3NL

Being an ardent fan and committed user of the Gray 108 viscous damped tonearm and its Japanese clones for monaural hifi applications, I needed to experience a modern iteration of a uni-pivot. This design actually dates back to the late 60s. Scroll down to page 1413 for the review in the Hi-Fi News November 1969 issue. The UA-70 seems to be essentially the same tonearm updated in the 70s with an anti-skate mechanism.

More Stax info at vinylengine.com

I added the UA-3NL to my collection in early 2018 and paired it with my Thorens TD124 and Sony TTS 2500, respectively. I was going to include this tonearm in my Alfred Bokrand AB309 write-up but one channel dropped out. 

When I finally accessed the internal hair-like strands of enameled wire, I realized that repairing it was beyond my DIY abilities.

Similar to the knife-edge bearing'd SME 3012, the Stax presents a mid to back row concert hall perspective, which is an atmospheric experience without any loss of detail. Although I've used it satisfactorily with the SPU#1S, it brings out the best from cartridges that track in the 1.5 > 2.5 gram range. Just like the SME 3012, the UA-3NL may not appeal to listeners who favor a front row seat/kick drum on your chest presentation.

Thanks to Steve's skill and nimble hands, I'm enjoying my UA-3NL again!

Tokyo Sound ST900

This 9" tonearm from the early 60s has an NHK broadcasting heritage. Comprehensive information about the ST900 is available at audio-heritage.jp. Surprisingly, the spindle to pivot mounting distance wasn't specified. 

So I took out my ancient Cart-Align protractor, did some measurements with my Ortofon SPU#1s cartridge attached and got a pivot to spindle distance of 223mm. I haven't had any problems with cartridges I installed conforming to the SPU's overhang.

Claus Volke and this Japanese audio blog have more to say about this tonearm.

It's equipped with a non-standard 4-pin connector in which the negative phase of the right channel is internally grounded. This limits its use to the stock plastic head shell. In an effort to make it compatible with modern metal head shells, I successfully detached the 4 pin connector at the base of the tonearm pillar. It turns out the ground connection was near the head shell collet, which I couldn't remove. Instead of risking damage, I relied on Steve's expertise.

The design may have been inspired by the Ortofon SMG212 and SKG212 with added Japanese innovations. It is quite massive and can easily balance a 30+ gram SPU. So far the lightest cartridge/head shell combo I used successfully was 19.5 grams. Given its high tolerance bearings, it's an ideal partner to the Denon DL103, Ortofon SPU, and similar low compliance cartridges. Consider this as an excellent alternative to the classic Ortofon AS/RM/SK/SMG 212 series tonearms especially if you prefer the svelte proportions of a compact plinth!

iPhone video clips of the MC cartridges and tonearms in action

"Fire" from The Elements

Joe Henderson + Alice Coltrane

Supex SD900 MKIVs + Stax UA-3NL 

Turntable: Thorens TD124

MC step up: Altec 15095A

Preamp: JE Labs Loctal

Amp: morrison micro 2A3 reimagined

Speakers: Altec 755C in Silbatone cabs

"All Or Nothing At All" 

from 

Freddie Hubbard's Open Sesame

Ortofon SPU GM(E) MKII + Tokyo Sound ST900

Turntable: Thorens TD124

MC step up: Altec 4722

Preamp: JE Labs Loctal

Amp: morrison micro 2A3 reimagined

Speakers: Altec 755C in Silbatone cabs

Steve, the master craftsman, and Ding

Looking forward to Steve's visit to the man cave!🍻

Fidelity Research FR64fx - dead channel fix

After many years of service, my FR64fx tonearm dropped one channel. 

I started sleuthing by studying the vertical pillar.

By peeling off the tonearm height scale (essentially an aluminum backed sticker), the set screws are exposed.

I loosened the set screws to carefully pull out the 5-pin DIN terminal + horizontal bearing housing from the vertical pillar. The unsoldered wire was instantly visible. 

After soldering the broken connection, I re-assembled in reverse order. I used rubber cement to secure the tonearm height scale back to the groove in the vertical pillar. 

Happy listening!

Gray Research HF500 Turntable + 108C Tonearm

My buddy John Piro has a knack for finding obscure vintage hifi pieces and has built up quite a collection. A couple of summers ago, he offered his spare blonde plinthed HF500. 

I had just acquired my first and only genuine Gray Research 108C viscous damped tonearm and couldn't pass up the opportunity to pair them up. 

Capstan Drive

The Gray Research HF500 turntable employs a unique drive system. Strictly speaking, it is not an idler drive. A round section rubber belt is partially embedded around the outer rim of the platter, which is driven directly by the motor shaft. Capstan drive is probably a more appropriate technical term.

45 + 78 rpm capstans

To change speeds, the corresponding 45 or 78 rpm capstan (or bushing as termed in the manual) is placed over the native 33 rpm motor shaft.

D&R turntable drive system
Courtesy of jamesvanarsdale.com

 AFAIK, the only turntable from this era which also drove the outer periphery of the platter is the equally rare D&R turntable, but as depicted above, it uses a rubber idler wheel. 

Seiko-Epson drive system
Courtesy of audio-heritage.jp

The Gray Research capstan drive may have been the inspiration for Mr. Takeshi Teragaki's three turntable designs for Seiko-Epson - ∑2000, ∑5000 and ∑5000II.

Servicing Tips

Download a pdf file of the Gray Research HF500 Manual for more detailed information.

This iron platter/bearing combination weighs close to 20 lbs. The 1" spindle tapers to 13/16" which turns on a 1/2" thrust sphere at the bottom of the sintered bearing well. 

After experimenting with a couple of belt sizes, a 3/16" (cross section diameter) x 36" polyurethane round belt x from McMaster Carr, catalog #3044K705 gave the steadiest stroboscope readings at all speeds.

Disassembly

Remove the four screws as indicated by the red arrows. 

The plinth lifts from the bottom frame. 

The top plate is a massive 1/4" thick metal resting on rubber pads at each corner. Prior to installation of new rubber pads, motor vibration could be felt at the tonearm finger lift.

 With new rubber pads installed (+ new motor mounts, see below), vibration was practically nil. The material I used looks very similar to replacement rubber soles used by shoemakers. 

Removing the motor 

To release the motor from the mounting bracket, straighten and pull out the cotter pins.

Left = worn out motor mounts
Right = fresh motor mounts

Another source of vibration were perished motor mounts. Brand new replacements are available from Surplus Sales of Nebraska -  Rubber Shock Mount, Part No. RPS - 426-0001.

 

New rubber mounts installed

Before reassembly, I cleaned the motor and re-lubricated the bearings with engine oil.

The sound is very energetic!

I've been enjoying my entire mono LP collection! 

View it in action! 😊