VPI Classic hum

Glad to hear. Please let us know how you fare.

I'm a very occasional lurker at Audiogon, and I came upon this thread while looking into maybe upgrading from my VPI Scout Signature TT (with SDS speed control) to perhaps a Classic 3. As my handle suggests, I do studio quality LP to CD transfers and remasters, often for commercial release. The persistent, if very low level these days, 60 Hz hum I've gotten from the TT and cart (a Shure M97xE with a JICO SAS stylus; no better sound for anything like the money) is mostly what has driven my thoughts about an upgrade. (BTW, I can easily and precisely notch out any 60 Hz + harmonics hum with software so it's not in my finished product, but still...) While I haven't read every word of it, I've found this thread useful and edifying, and I thought I might add some different suggestions.

As implied, I don't use this TT for general listening. My system setup is such that the signal goes directly from the TT via unbalanced Monoprice ID#2680 RG-6/U 18AWG 75 Ohm Coaxial cable (I auditioned several interconnects up to $200/pair and none were as good, and for $7.50/pair!) to a Musical Fidelity M1ViNL phono stage directly connected with balanced cables to a Mytec Stereo96 ADC and then via Toslink to my DAW (Digital Audio Workstation). Thus I am able to very clearly SEE in real time with spectral analysis, as well as hear, exactly what I am getting and the effect of any change I make.

Cables, and their position, ARE important, and it's rather surprising how evident the microphonic effects can be when the cable from the TT is moved even slightly. Cabling is also a significant reason why I've been considering moving to a Classic 3, as that can be had with balanced outputs which have the potential to eliminate essentially all spurious RF and AC pickup.

But the other hum-killer that no one seems to have mentioned in this thread is balanced AC power. With balanced AC, instead of a 120v hot and 0v neutral leg as is normal, there is 60v 180º out-of-phase on BOTH AC legs, which will naturally cancel most AC noise. Converting one's system power to balanced AC is easy, but it requires a big, heavy, well-designed and expensive transformer, and prices start around $1500 and rapidly go up. Equi=Tech is hands down the best manufacturer of such equipment, and THEY AIN'T CHEAP at all, but boy is it worth it if AC hum is a problem. Their website is full of good and valuable information.

BTW, another often unnoticed source of AC hum are these damned compact fluorescent light bulbs. They'll generate a whole LOT of hash and can cause interference if they are anywhere near your equipment. Running them with balanced AC helps that tremendously as well.

A couple of things that no doubt go without saying around here, but I'll say them anyway. First, hum and RF pickup are completely separate and different issues from acoustic feedback problems. I don't have acoustic problems because I play my monitors at a very low level while transcribing an LP. Also, DO NOT LIFT GROUNDS, ever, which people sometimes do to fight hum. Proper grounding is important, including from the TT to the system, but it's especially important if balanced AC is being used. ALL modern electrical equipment is compatible with balanced AC, but if there is a fault, you could get hurt or worse if your grounding is improper.

Well, enough for now. Hope this helps.

RE" Meanwhile, let's hope this 31-month-old thread will finally stop cropping up!"

HA!

M~

Macster - No, it won't! Lol...

Lp2Cd - Interesting you should bring up the issue of balanced AC power. In fact, that's how I've been running my system for years. I've got a dedicated 32amp spur running from the mains to my room and the balanced transformer is plugged into this, from which my system is powered. So far, so good, no noise ... except from my first VPI Classic which appeared to be feeding motor hum into the cartridge via the LP surface. And I never lift grounds.

It's just physics. The motor is too close to the cartridge. They either need to shield the motor better or move the motor farther away. Sure certain carts will be more immune to the effects but you should not have to worry about this on a product this mature.