I just got my Newcomb TR-1640, and this thing is fantastic! It was an eBay purchase, so always a gamble, but this machine just works great and sounds so good! It doesn't even have the legendary magnetic cartridge. I've just finished listening to 10 assorted 16" transcription records, a couple 78's and LP's, and not only do they all sound really good, but it works flawlessly, and man can it crank out the audio with those PP EL84's and twin 12 inch dual speakers!

So tell me again why I should consider changing from the stock ceramic to a magnetic cartridge? Is it really that much better?

Garret

If you were a record you could tell the difference. But if it sounds fine the way it is, no need. The mag needs an equalized gain stage the ceramic version does not provide. A high-compliance mag might not be happy living in that arm.

So this means the original ceramic cartridge is more damaging to the records? I didn't realize that. Why is it?

Thats rubbish, properly setup a tonearm with a ceramic catridge will not harm records.
The real difference is a magnetic catridge has better frequency response, but its pointless with 78 records or older lps, there is nothing to gain.

Ceramic produces more signal, which is not free. Energy to do so has to come from the stylus. Magnetic (in general) requires less force from the vinyl and thus deforms it less.

Not just any cartridge works with just any arm. The cartridge that came with it most likely matches the rest of the set most closely.

If the native cartridge is old (they stiffen with age) or mono, it is highly advisable to upgrade to a comparable stereo cartridge unless everything you plan to play on it is also mono.

No offense, OMM, but compliance is not rubbish. Compliance is why my 45yo vinyl still sounds new. But the system must be compliant, not just the cartridge.

I never said compliance was rubbish, but as you said yourself you cant shove a magnetic cart on a 50 year old turntable and expect it to play nice.
In some cases it will do more harm than good and not track properly.

Ok, so it's the higher tracking force that causes the greater wear. This tonearm has switchable force for 78's or LP's, of course I have no idea what the force is, but I can and will measure it later.

I've been checking it out inside, and it does not have a 12AX7 preamp, and there appears to be no place for one on the chassis. However it does have a stereo cartridge, which is indicated also on the schematic pasted to the interior. There is an extra jack for stereo which is wired to the other side of the cartridge. This all appears completely factory.

Just thinking about this makes me wish I had saved my dad's old Dual turntable and the Shure M-something cartridge I bought for it in the late 70's. I think it was thrown out in the trash years after I moved out, along with the Eico ST70 amplifier. The KLH speakers are still there though.

Thanks for the advice. Right now I'm hard pressed to change anything, as this thing really works and sounds great.

Garret

In that case just enjoy it

If you study the physical design aspects of ceramics vs, magnetics, it's clear that yes they're more gentle on records in the long run.

However as stated, ceramics can be relatively gentle too, if properly balanced, and in a freely pivoting tonearm.

A lot of this has to do with compliance - and the stiffer the needle is when tracking a groove, the more wear and tear is imposed on the record.
Another thing to consider is moving MASS - the needle, cantelever - in this case smaller is better.
A big honking cantelever is like rowing a boat with a sequoia tree trunk.

The spec I was able to find was tracking = 7.5gr. You decide what that does to records.

You win.

It's not mag vs. cer, mV vs. V, you vs. me. A GE VR2 @ 4gr might be a wear improvement over a 7.5gr ceramic, but it might be relatively unhappy living in that arm, even properly counterbalanced (if possible). Can't just alter one component and revise the entire system dynamic.

If it works for what you're using it for, don't fix it.

Ceramic, and, magnetic cartridges are NOT interchangeable.
Sounds like you have a 64 model with min. tubes. Perhaps a pair of 6BQ5 output?
I'm not familiar with this model...
May I see pictures of this machine? Arm, cartridge, and, amplifier?
Thanks.
Bill Cahill
I assume this is a transcription turntable??

OP said he played 16" on it, for what that tells you. A Garrard RC88 won't do that.

OTOH, RC88 optimally supports a Shure M3D and this machine almost certainly would not, even if the amp were supplemented/modified to accomodate the needs of magnetic.

It's not "one or the other". It's more what the machine was designed to accomodate. The further one deviates from that, the more one is obligated to understand the system dynamics.

As I said in my first post, this is a "Newcomb" player, not a "Garrard". Those danged old eyes getting us again...

This is a Newcomb institutional style player, apparently a higher-end model, except for the cartridge. It is a TR-1640, very simlilar to the apparently more common TR-1640M. Notice the "M" on the end.

To decode the model number:

"TR" = Transcription
"16" = Capable of up to 16-inch diameter records
"40" = Max Power output in Watts
"M" = Designed for "Magnetic" cartridge. WHICH MINE IS NOT. Mine does not have the "M".

The "M" version apparently means it has a magnetic cartridge. Mine does NOT have the "M". Mine does NOT have a magnetic cartridge. I do not know what the other differences are in the tone arm, if any. I do know my version does NOT have the 12AX7 phono preamp, although looking at the two schematics, it should be very easy to add one, if I choose to.

My phono came with the optional Quantity of 2, 12" dual woofer-tweeter Permanent Magnet speakers. So mine has 4 speakers in two portable speaker boxes. Did I mention this thing is really loud!

The tone arm has two tracking force settings. I just measured as:

LP mode = 9 grams
78 mode = 18 grams

That seems higher than I remember from my old HiFi days when I used Shure M97 or something like that.
The force appears to be set with a spring, so it should be easy to change, if ever needed.

Mine does have EL84/6BQ5 miniature tubes. It has 4 speeds, and has a "Stereo" output jack for the other channel from the stock stereo cartridge. It is shown in the schematic, and mentioned on the printing on top to use a "Stereo" cartridge.

My goal with purchasing it is to be able to convert these old 16" transcription records into a high-quality lossless digital format. But this thing works so well, I don't want to mess with it. The amp's noise level is amazingly low, especially for not having any caps changed. Not a bit of hum.

Bill, I'll get some photos soon.

Garret

I would not agree with those output power ratings. My TR-1625M has push-pull 6V6s which are good for 12-15 watts max, and the most you can get from PP 6BQ5/EL84s is 15-20 watts.

-David

In those days FTC (is that an F word?) still allowed rating by 'peak power' which was just RMS X2. EICO rated their EL84 sets at 12-14W.

I only dragged RC88/M3D in for contrast/comparison. Coulda was AT6/M55E. Both cartridges are magnetic and neither would be the least bit happy in the Newcomb arm, 12AX7 notwithstanding.

Here's a Shure SC25 magnetic cartridge in my Newcomb TR-1625M. Tracks perfectly at 3 grams.



Here's the tone arm wiring to strap the cartridge for mono:



Here's the spring adjustment for stylus pressure. Range was plenty to get down to 3 grams.



Here's the 12AX7 preamp stage. The green arrows point out the input resistor that was changed to 47K.



-David

In the photos I've seen, the "M" version appears to have the same arm as mine. So is the GE VR cartridge just more forgiving and therefore works ok in the Newcomb arm where other magnetic cartridges don't, or is do the arms just look the same, but really aren't?

I've read several recommendations for replacement of the GE VR cartridge with a modern Stanton, and they usually claim superior results from the modern Stanton.

I'm just trying to learn, I'm not necessarily going to do anything with it right now.

GE VR2 is pretty versatile. Likes to track around 4 grams. Plays 78s and microgrooves by flipping stylii. I don't believe there was ever a stereo-compatible version but I could have missed it, I'd moved on from GEs to Shures by then.

A current Stanton would be superior to the GE. But I *think* you might find an appropriate current ceramic that operated in the lower range of your tracking force adjustment and would not require electronic modification. It probably should be rated for at least 3 grams, the arm's suspension and pivot may not support less than that.

Magnetic tends to be flatter and can track lighter, down to the limit of the arm. Might be worth it to convert your 1640 to M version. But speaker limitations may limit the benefits over a 3-gram ceramic.