Both systems have been fully set up, and I have recorded test audio from various records (pop, piano solo, quartet).
The below analysis of the recorded audio was made after consulting our resident expert in perceptual testing. A key point that was emphasized was that we should first set up the 2 systems, and listen to the audio. If we ourselves could tell the difference, then the test is too easy: we should increase the difficulty of the task (i.e., replace components in the signal chain with "better" devices).
My initial impression was that the difference between the 2 systems was quite obvious in 2 regards: overall loudness (advantage: expensive), and brightness (advantage: cheaper). The first of these can be somewhat reduced using the Steelhead front panel controls, reducing the output gain from 55 -> 50 dB, and increasing the load from 50 -> 100 ohms.
Once this was done, samples were re-recorded, and the second of these 2 issues was still a problem. While I have used the term "brightness", it is as much of a HF emphasis that can be heard in the less expensive setup, as it is a mid-range emphasis that is heard in the more expensive setup. Note that I am not making a judgment of the quality of either representation, but rather just a comparison between the 2 systems, which is quite obvious from even the first listening. If we plan to present these 2 versions to listeners, the difference may be too obvious, and perhaps we should be looking for a more apt comparison.
That said, I decided to try to identify the contribution of each component in both systems to the overall sound. First, I recorded samples of the less expensive system using the cables that were originally connecting the more expensive setup. No difference. Next I referred to the RIAA error charts. The Steelhead does have a greater mid-range boost than the GSP preamp. Perhaps this was the cause? So I connected the output of the HR-X to the GSP. The result still sounded like the original output of the more expensive setup. So the only remaining factors are the turntable or cartridge (most likely) itself.
To truly test these, we will need to either swap cartridges on the turntables, or accept that the cartridge comparison that we are making is too discernible.
Audio examples for the above conditions are available upon request.
Hi, I am very interested in your research. It's an excellent project. I myself am writing a dissertation on the history of the high fidelity business and audiophile culture. A few comments/queries:
ReplyDelete1) Your findings go against typical expectations because moving coils have a rising high frequency response due to tip resonance. [That said, I had a similar Ortofon moving magnet and found it bright.]
a) Do the samples have a different spectrum if you line them up and compare?
b) Have you optimized the capacitance of the cable/phono stage for the OM20? Cable capacitance can have a rather large effect on frequency response for moving magnets.
c) Have you measured the distortion? Distortion could sound like brightness. [My guess is this is the issue.]
2. You left out a possibility: the tonearm. One is a 12 inch model the other 10 inch, which gives different resonance, inertia, and tracing distortion.
3. You could eliminate that as a factor by obtaining a second JMW 10.5 base and armboard for the HRX. That would allow you to switch arm/cartridge as one between tables rather than reinstalling, which is time consumer and risks messing up the comparability of the alignment.
4. Do you have plans to test a more moderate system in the future, perhaps a turntable that is under $1000 and a phono stage under $500?
5. When you record the turntable outputs are you also monitoring through speakers, and at what volume? One of the differences between the two turntables is how they isolate from acoustic feedback, which will be lessened if the playback is muted.
6. Depending on installation, it is possible to get an Aries to sound bright because of vibrations from the motor unit. If you take off the belt, turn on the motor, and put the needle on the platter, you can see if you are getting breakthrough. That happened to me until I put something compliant under the motor (a carpet remnant).
Hi Marquis,
ReplyDeleteInteresting comments/questions! :)
I'll try to answer these as best as I can.
1) This is true, and I was quite surprised at it as well. As we are attempting to find systems that are comparable, we have since replaced the OM20 with a DL 103 and added a GSP Elevator EXP for a step-up.
2) We haven't yet performed spectral analysis on the full systems. We are planning on doing this once the listening tests are done.
3) When the OM20 was being used, we were connecting the Aries output directly into the Jazz Club, on its RIAA/CCIR setting. As these are the only available settings, we've left it at that.
4) Yes. We are starting with these, however the idea is to first determine if expert listeners can identify a difference between the 2 systems. My guess is that the difference between the expensive and "economy(?)" systems will be much greater, so we've begun with this.
5) We are planning to run the test using headphones. The output of the GSP combination is fixed, so we are adjusting the output of the Manley such that it matches that of the GSP combination.
6) Interesting–I hadn't thought about that. I just checked, and no. We've got quite a solid table that we are using, but nonetheless, I'll see what I can do about getting a carpet remnant.
Thanks for your suggestions! :)
Jason