guy sergeant wrote:

On the Ortofon website those models of the SPU which don't come with inbuilt transformers, have a recommended load of >100 ohm. Using the cartridge into too low an impedance load definitely does lift the lower frequencies. Too high and the upper mid/HF is emphasised. You may want to try a little higher than 90R. I'm glad to hear you're enjoying it....

Ortofon unfortunately does not publish how to load the SPU. In thier site they said 47Kohm but this is, am sure, for a transformers bult-in. Probably they never publish the recommended load for their “raw” SPU cartridges because they would like people to think that SPU are identical to the Ortofon not-SPU model and consequentially people might use the default Ortofon step-up transformers. Probably it is too much for a conspiracy theorists and particularly form me – the person who it not well familiar with Ortofons.

Here is how I see it is and I do not think that it is very far from what it is. Ortofon SPU Mono is very atypically high impedance (DCR) cartridge with a lot wire inside – it is 100Ohm. The MC cartridges usually should be loaded into 2-3 times of their DCR. This would make 200R-300R an optimum impedance for SPU Mono. I ended up running it into 26dB transformer and 90K load that end up with 90K/676=133R. It is at the lower side but as I said I like to overload the cartridges and it sounds very fine to me now.

Still, despite of the “loading secrecy” that Ortofon looks like spared around this needle I very glad that I unrolled into this projects.

Rgs,
The Cat

I juts got home, put a record to play and suddenly discovered that my SPU has it’s cantilever bent 90 degree and then even twisted vertically. It was perfectly fine last night!!! I have no idea what kind forced what applied to it and particularly how it happened but it look that it dead now. I tried to straight the cantilever up but it dose not look kosher for me after I have done it. I really like the cartridge and I would like to continue to use it. Is anyone knows who replaces cantilevers on the Ortofon SPU? I heard Van den Hul does those types of surgeries but I am sure thathe will not put the original needle but his long profile version. Is anyone else does it? Perhaps Ortofon does it? Certainly if all goers wrong then I will buy another one but it is kind of shame to trash practically new cartridge…

The caT

Brian Clark wrote:

Best contact Ortofon in Denmark and arrange through them (unless you bought through a US dealer). They will send you another one on receipt of the damaged one. Charge you replacement cost for it though - compare with Japanese price for new. Bad luck Romy, is Koshka looking sheepish?

I ended up getting another one. So unpractical but it is what it is. Now I have practically new SPU-motor with no needle - so sad- what can do with it! Another sad part of that mysteries story that I have no recollection or a slightest idea when and how it might happen. Thos high mass tonearms are always expose an extra vulnerability on the cartridges but I always kind of knew before that I did something wrong and that the certain accidental actions of mine did the specific damage. In this care I juts did not catch how it happened! My Cat does not go to my TT and there was no one in my room since I was not broken. Mentally I settled down with an idea that someone broke-in into my room, destroyed the SPU’s cantilever and escaped. Isn’t too much for a person who pretends to have remove sights of intelligence?

:-)
The caT

Brian,

Thanks again, I heard about this guy but never dealt with him or heard his cartridges. Can you dig his phone number or his email (I do not do faxes)? Certainly it is t might be an interesting opportunity to do something with it. My current SPU has a note “DIAM.25”

Rgs,
Romy

Who know anything about this needle?

I am playing now this CG-25 - my new Ortofon replacement. This new cartridge is turn out to be “MONO CG 25 Di”. It looks and feel completely different and this CG-25 is what I called the TRUE mono cartridge. It has one single coil with a single pair of contacts. So, it is not the regular SPU cartridge strapped in mono setting.

This CG-25 is heavier and has a half of output of SPU MONO. However, the differents on the output voltage is not auditable and I use the same “clicks” on my preamp. According to Ortofon the CG-25 has more reasonable 2R of internal DCR and should be loaded into >100R. I drive CG-25 into the no-step-up, directly to my two stages, penthod-input, air-cap phonocorrector, the very same that I used for the SPU MONO, and use the very same arm and the same all the rest settings.

To my surprise it sounds like the CG-25 is actually even better then SPU MONO. It has SCIENTIFICALLY less surface nose then I had with SPU MONO, although the SPU MONO have it way less then stereo cartridges. It looks like the CG-25 has less “upperbass forwardness” then the SPU MONO. Is it due to the differents of the internal impedance (100Rvs 2R) or because any other reasons I do not know but it all together sounds more “compiled” tonally.

The CG-25 does sound slightly sharper and less lush then SPU MONO. Certainly I do make a correction that this cartridge is juts out of box.  I remember how the SPU MONO sounded brand new and the CG-25 is more vigor. Probably it is because the CG-25 has way shorter cantilever that reduces the compliance of the cartridge. As the result, my tonearm “sounds” with less effective mass for the given cartridges. Anyhow, I find the this change is somehow beneficial at this point and my new CG-25 has less “Ortofonissness” and more sounds like a normal neutral cartridge  (closer to Shelter?)

In any case, I did not play with masses, VTFs, VTAs and with anything else, letting this needle to run for a few days and settle down. Certainly it is a slightly different animal then the SPU MONO, still very pleasant but with less attitude. I will let know how it will work out for me.

Regarding the SPU MONO: Thanks again, Brian. Sometimes later I will contact the European guys with fixing my killed in actions SPU MONO. Who knows, perhaps in a week or two I will not have any motivation to do so….

So, I hope…
The Cat

Romy the Cat wrote:

I juts got home, put a record to play and suddenly discovered that my SPU has it’s cantilever bent 90 degree and then even twisted vertically. It was perfectly fine last night!!! I have no idea what kind forced what applied to it and particularly how it happened but it look that it dead now.

Brian Clark wrote:

What you have there Romy is essentially the cartridge Ortofon introduced in 1948, the first production moving coil cartridge. The motor is the same, just the "suspension" material changed from india rubber to a modern elastomer AFAIK. Also the G-style headshell only dates from 1959 (SPU introduction). I will be VERY interested in your more thorough evaluation. I hummed and hawed between the CG 25Dia and the SPU Mono before springing for the latter, expected next week. My speakers could do with a bit of upper bass help. I will be playing with both SME 3012 Series 2 and Series 1, the latter expressly developed for the SPU and also used by Neumann for playback of acetates on their cutting lathes.

Rgs,
The Cat

BTW: the SME 3012 Series 1 use heavier tube and have heavier affective mass, so it should be more suitable to the 25Dia

Romy the Cat wrote:

<P> When you used your 25Dia then can you recall a similar experience at the beginning of the cartridge live (sharpness and bass)? </P>

<P> If this cartridge is replica of the 1948 model then it should use a hugely heavy arm. No wonder that Ortofon does not quote its compliance on thier web site: presumably they did not want to scare people. I can actual see the there is not complaints in the cantilever when I lower this thing in the groove.</P>

Brian Clark wrote:

Yes, that cartridge has NO vertical compliance AT ALL. Keep it away from your precious stereo pressings at all costs!

Romy the Cat wrote:

This is funny that you, the British guy, buy a European made cartridge in Japan…

Brian Clark wrote:

I will be VERY interested in your more thorough evaluation. I hummed and hawed between the CG 25Dia and the SPU Mono before springing for the latter, expected next week. My speakers could do with a bit of upper bass help.

It was in interesting day: I spent most of it listing. I friend of mine sent me a new amp to test, the new Mono cartridge, a pile of new records….

The 25Dia lost some of it's virginity and I did play with it a little. Generally I was able to get the bass out of it and it now does OK bass.  As I said before – the 25Dia is more neutral and more high-tech sounding cartridge then SPU-mono. It more evenly balanced faster and less attracting attention to itself. It slightly zippier then I would like, perhaps it will go away in a few days. However, despite that I feel that 25Dia is higher performance cartridge I still feel that the sound of SPU has own rational, even more: now I am missing it. That SPU’s upper bass forwardness (about witch I complained) combined with some softness and the subdued flashiness was very interesting and created own delightfulness and beauty. I understand that it was sort of glorification of music, even up to the point of embellishment, but it had own sense and at the level HOW it was done I find it was very interesting.

Now I am spinning the Beecham’s “Carmen” with Victoria de los Angeles form 1952. I wrapped my tweeters in toilet paper and it sound more or less OK. With SPU I did not use the toilet paper on my tweeters. Also the voices and instruments sounded with SPU kind of reached and nobler… Perhaps the SPU and 25Dia have the different breaking-in patterns. Will see in a week…

Rgs,
The cat

Thank you Brian - you confirmed what I feared. 

Caveat emptor.  The seller is the former Van denHul repair guy in Germany -  Detlev Brod.  He offered a new SPU mono, at a price too good to be true.  I specified the GM25, and when I contacted him to inform him of the error, he told me that it doesn't matter - they are both monos!!!!!

since these are conical styli, is there any downside to retipping with a "non-Ortofon" stylus.  Assuming the retipping is done properly?  Does supension, compliance, output, or something else change?

scott

skushino wrote:

Thank you Brian - you confirmed what I feared.Caveat emptor. The seller is the former Van denHul repair guy in Germany - Detlev Brod. He offered a new SPU mono, at a price too good to be true. I specified the GM25, and when I contacted him to inform him of the error, he told me that it doesn't matter - they are both monos!!!!!

Since these are conical styli, is there any downside to retipping with a "non-Ortofon" stylus.Assuming the retipping is done properly? Does supension, compliance, output, or something else change?

Brian Clark wrote:

Perhaps Zyx will come out with a mono cart one day soon since they are now fashionable. Brian.

Sorry to be responding to an old post but ZYX has just released a mono cart which costs less than 400 dollars in Japan.
I found out when I was recently lectured on how all stereo MCs are flawed in channel balance because ZYX has got the patents on the remedy. They all lack “real stereo” which leads to compromised stereo imaging and S/N ratio.

Now, Romy has taught us to think about what is missing or wrong with the sound first before we upgrade, and I think that is very good advice. I am therefore rather skeptical and am in no rush to dump my Ikeda and Koetsu.

But, I was told that this phenomenon is very easily verifiable by playing left and right speakers separately and noticing big imbalance for non-ZYX carts.