Seduction with Stereomour?

[Paul Joppa]

I recommend you experiment with the stepup ratio; the cartridge/transformer interaction is complex and difficult to predict. For example, the DL-103 is said to have 100 ohms impedance, which stepped up by 20:1 (26dB) becomes 40K ohms. Running that into the 47K Seduction input gives a net 21dB gain - and also provides nearly 1:1 damping. This is what I would use to start with, and gives about the most gain you can get from a transformer into the stock (RIAA standard) 47K load. Transformer ratios of 20-30dB won't change the net actual gain more than a dB or so, but they will change the cartridge damping and the transformer's high frequency behavior.

Of course, I got the 100 ohm figure for the DL103 off the internet, I didn't measure it myself, so I can't be sure it's correct.

[Downhome Upstate]

I believe I read in a few places that the SUT will see the DL-103 as presenting 40 ohms. I'll have to go back and look again.

[Downhome Upstate]

What is the difference between a cartridge's output impedence (40 ohms for the DL-103) and load impedance (100 ohms)?

[Paul Joppa]

I believe I read in a few places that the SUT will see the DL-103 as presenting 40 ohms. I'll have to go back and look again.

That sounds more reasonable, actually. In that case, the 30dB turns ratio would give 25dB net, probably best for Seduction - if the damping and transformer HF response are good.

Guess I should just stick with the recommendation to try different ratios once you have the transformer.

[Downhome Upstate]

Just placed my Seduction order - looking forward to it! Hey, Doc, where's that photo with the model holding the Seduction at thorax level? That is such a great picture!

An Asylum inmate is selling me his armless Kenwood KD-500 'table for $150. I've got a Jelco SA-750DB for it: I'll need to drill out the existing armboard to 30 mm. He's also sending over a Hammond box with Cinemag 3440's, currently wired at 1:30/37.5 Ohms. Think I'll try the 1:18, 150 ohm setting when I plunk down for a DL-103 or 103R.

Addictive, this is. Gotta love it.

[Grainger49]

Back some months ago I was using my vintage DL-103C with my setup.  I have a buddy using a new DL-103 with my old Seduction and my Denon SUT.  Both worked perfectly with the Denon SUT.  Right now I am out of town so I can't look up the specs on it.  

BTW, Paul Joppa gave some good information about the needed turns ratios and impedances on transformers some time back.  I expect it is in the phono folder.

[Downhome Upstate]

Back some months ago I was using my vintage DL-103C with my setup.  I have a buddy using a new DL-103 with my old Seduction and my Denon SUT.  Both worked perfectly with the Denon SUT.  Right now I am out of town so I can't look up the specs on it.  

BTW, Paul Joppa gave some good information about the needed turns ratios and impedances on transformers some time back.  I expect it is in the phono folder.

Do you remember the turns ratio used with the Denon SUT?

[Paul Birkeland]

The DL-103R has ~0.25mV of output, the DL-103 0.3mV.

I've successfully used a Seduction with cartridges rated at 6.8mV, and the balance of gain was outstanding.  To get there with 0.25mV, you'd want a voltage step-up of about 1:20.

With a voltage step-up of 1:30, you'll end up with ~7.5mV, which is potentially too much, but give it a try anyway, on that Cinemag unit, it's more like 1:36, which will push it even higher.  I think the 1:18 should work really well!

-PB

[Grainger49]

I'll mark this thread unread and look up the specs when I get back home.

[Paul Joppa]

I don't have the numbers handy, but as I recall the DL-103 has a DC resistance comparable to the resistive impedance load presented by the stepup transformer/Seduction combination. That means a substantial signal reduction; if the resistances are matched it cuts the voltage in half (-6dB). Some enthusiasts think that is a good option, providing some damping of the vinyl/tip mass resonance.

[Grainger49]

It seems that the instructions ended up with my friend who is borrowing the SUT right now.  I will contact him tonight and see if he can locate the specs.

[Downhome Upstate]

I have determined that discretion is the better part of valor here.  Accordingly, I will be advancing to the rear, with dignity.

Placed an order for the Audio Technica AT7V, a low compliance, low tip mass MM design with 5 mv out that should be a great match for the Jelco arm and the Seduction.

God willing, I will live to screw around with LOMC cartridge loading another day.