Gain and Loading

I played with loading on a DIY tube Phono I had no manual for, I used headphones to avoid any potential damage to speakers, worked well and the headphones were great to really hear the at times subtle adjustments.
BTW I have the Dyna 20L, isnt the H a high putput? It should work as a MM and thats an easy set-up in general.

I would minimize the gain consistent with a full robust sound, making sure that your pre-amp can work within the range of attenuation that is comfortable with your ears and provide fine enough volume adjustment. With a 2.5 mV output you should not need it on a high gain setting, but its also dependent on total system gain. As for cart loading, I think that that is highly system/cart dependent but in general high output MCs are typically loaded as if they were MMs. But there really is no way to harm your rig as you alter loading, so experiment til you find what sounds best.

What exactly is loading? I have an okay understanding of gain since I've been trying to roughly calculate the dB I'd need to achieve normalization with my CD.

Tfk, what preamp are you using? I've been searching for a decent preamp that has at least an adjustable gain. I doubt I need a high-gain preamp since the cartridge I'm using is a 6.5mV MM.

Gain: given the cartridge output, 40-50dB would be indicated. If you have a normal cdp, try to get similar amplitude (i.e. ~2V entering the pre section.

Loading: >1000 is hardly specific. While 47k ohm is standard for MM, it would be best if you could:
a) ask Dyna for their recommendation
b) ask Dyna for the cartridge inductance. Then you can compute the resistive loading as: sq rt L/C (or go to Hagerman's site to do it).

Failing all that, try 43-46-50dB gain & choose which gives the best frequency extension and THEN go down from 47k until you find the best setting...

Tfk, I think you're fine as-is. Just plug that cart into your phonostage. Likely you won't have to change a thing.

jh

Tom: Depending on the rest of your system, 50 db of gain may be putting you into an overload situation. If you can do it, I would suggest getting as close to 42 db as possible for gain and starting with the 47K loading. From there, you can experiment up or down with loading, but I would certainly dial the gain down from 50 db as a start and at least try that out. I would think that the sound should be improved with the lower gain.

Thanks for all the responses so far.

Hdm, how do I know if I'm in an overload situation? Distortion at musical peaks? My next adjustment down is to 44db, so that might be a good setting, huh?

Cheers.

Tom: Overload could be indicated by distortion if it is really heavy duty, or it could just manifest itself as a more aggressive, strident quality to the music. Ideally, all things being equal (which of course they never are) your 2.5 mv output cartridge requires right around 42 db of gain, so 44 should sound much more realistic and natural than 50. On the other hand, if you undershoot the 42 and go into the mid 30s, the sound will probably take on an anemic quality compromising the dynamics cosiderably.

My experience is that if you're within 2-3 db you are probably ok, get to 5-6 db over or under and you are seriously compromising what your cartridge is capable of and getting inferior sound. My suggestion would be to try the 44 db. for a good period of time (maybe a week or so), then switch higher or lower.

I would guess that would be the best setting for you. You
will also find that, if you also use a CD player, you will have to crank the volume on your preamp considerably more with vinyl, possibly between 10 AM and up to even 1 PM if you listen at high volumes but that would be quite normal.

Dialing in gain with high output moving coils can be especially problematic as almost all phono stages are optimized for moving magnets with a higher output than your cartridge or low ouput moving coils with considerably lower output that require much more gain. But that 44 db setting should work quite well.

One approach to adjusting the load resistance is to start at 47K ohms, as you have done, and gradually reduce the value while noting any changes in apparent gain. When the volume at a given gain setting starts to decrease in relation to reducing the load resistance, then you have gone too far. Go back up to a value that gave no perceptible (or measurable if possible) loss of gain compared to the 47K ohm value. Choose any load resistance between the "critical" one that you determined experimentally and 47K, based on your listening preference.

Second the 44db gain setting as probably being appropriate.

What load settings are available to you on this unit? It is likely there are very limited settings, if any, between 47K and 1K anyway. As you go lower the most obvious difference you'll hear is smoother high frequencies. If the highs are not rough at 47K then you're probably fine but trying your options won't hurt.