Need Help From the Denon Zu Heads

[thebes]

Or anyone else for that matter.

Our own Mike Lindsey has generously offered to lend me his
ZU modded Denon 103 . It would be mounted on a stock Rega RB300 tonearm and
from reading the main Zu thread I do believe the arm can take it. I have some additional weighting I could add
should it be needed.

However, I’m wondering if it could be used effectively with
my Anthem Pre1 preamplifier without a step-up transformer. It does have
High/Low gain switches and all the specs on the pre are detailed at the end of
the Pre1 Adobe download at this link.

(Sorry couldn’t figure out a way to post them here).:

http://www.anthemav.com/oldsitev1/frames/manuals2fr.html

My Anthem Pre1 also has the option of adding cartridge
loading resistance and capacitance via the addition of resistors and capacitors
in available slots on the circuit board. There’s a description in the afore
linked manual and see Questions 20 and 21 in the following FAQ link for more
details:

http://www.anthemav.com/oldsitev1/pages/faq.html

All this technical stuff gives me a large headache (Zin and
Zrec getta outta here!) but I sure would like to give this a whirl, so I”m asking if I can do this without a step-up
transformer with a possible improvement over my current Ortofon Super OM40 mm
cart.

[LarryC]

I sure would like to give this a whirl, so I”m asking if I can do this without a step-up transformer with a possible improvement over my current Ortofon Super OM40 mm cart.

Marty, I'll spin out some theoretical stuff, but of course you need someone with actual experience to chime in here. The Zu seems to have an output of only 0.3 mv. It's been a while since I used anything that low, but I know that needs a lot of phono gain.

For example, the KAB online phono gain computer says that output requires 60 db in phono stage gain alone (without factoring in linestage gain). I struggled for a long time with trying to run such a low-output cart with only 46 db phono gain, and can say it's almost not worth it. Big disadvantages were high noise (hiss) level, and a lack of bass fullness and impact. Higher gain solved both those issues.

The Anthem specs are hard to figure out, as we know. My guess from the manual was that the lower phonostage gain mybe was 32 db and the higher maybe 49 db. If so, the latter might be touch and go with the Zu, especially on LPs cut at a low level. Can you confirm the gain figures with Anthem directly? Ask them about the Denon/0.3 mv carts while you're at it.

My feeling is that, as good as your earlier Ortofon sounded to me, a PROPERLY AMPLIFIED MC cart should have the edge in transparency and closeness to the real music -- but that it might sound a little thin, noisy, and not at its full potential if it it's not.

Is there any way to transport your 'table/arm/Zu up here if you decide to give it a try?. We'd have to figure out a way to plug it into my 61-db phono input, and that won't be easy.

[thebes]

As always thanks very much for your delving into this for me Larry.

I'm asking this here because several folks have tried these out and I'm not sure all of them have used a step-up tranformers or the "Cream" option Mark provides.

As far as this stuff goes Anthem and Sonic Frontiers are basically defunct and live on as Parts Connexxtion. I'm leery of of what advice I might get from them because they sell "upgrades" to these units and I'm not sure I'd be getting a sales pitch rather than unbiased advice.

Hopefully other parts of the Klipsch forum brain trust will be checking in.

[leok]

Have you seen:

http://www.stereophile.com/phonocartridges/1207zu/

The Anthem claims to handle 0.2mV devices (Hi gain setting) and the Denon has a 0.3mV spec. so I would expect it to work.

The 47KOhm input resistor on the Anthem certainly meets the >100 Ohms Denon requirement. Trying a bit lower (1KOhm, for example) might tighten up the sound a bit. The Anthem instructions mention possibility of changing the load resistor. You or someone may have added a capacitance to the Anthem phono loading for MM and, if so, I think you might want to remove that for the Denon.

I think I modified my Creek to no cap and 1KOhm or 2.2KOhm load when I changed from MM to the Benz Ace.

Leo

[thebes]

Leo you are the Man!

Neither Larry nor I spotted that reference in the body of the manual (I've now found it). I kept looking at the specs at the back and scratching my head.

I have checked the extra slots for both loading and capacitance and they are empty with a 47 resistor sitting right above them.

I gather what you are saying is that after installing the cart if I found the highs to be too strident I could add in a 1K resistors to the slots, thus lowering resistance to 46K and if needed, go down from there.

Hope all is well with you and your lovely wife. Do you ever get down here to visit your brother? Why don't you come down for a Fall visit when a few of us will probably be taking in a concert at an amazing venue called the Strathmore Performing Center.

[leok]

Well, I was really thinking of going directly from 47KOhms to something like 2.2 or 1 KOhms (replacing the 47K). Output impedance of MC is very low. Your take on the intent is what I have in mind.

I haven't been to DC since the last time Martha and I stopped by. Since then my brother has picked up a pair of Forte-IIs. I'll be down sometime to upgrade the crossovers. Meanwhile he's quite happy with the Fortes and one of my P6D amps. When I make the trip I'll see if we can arrange something, maybe with a concert at the Strathmore PC.

Leo

[thebes]

Hmmm. I get it. It would seem that the way I was thinking would increase the resistance instead of lowering it. Maybe I should add some capacitance, which I presume would increase the output, instead. I do have both options. But first an install and a good listen.

Not familiar with a P6D amp but knowing you I'm sure it mates well with those Fortes.

Glad to see you might get on down here.

Leo's coming! Leo's coming!

[leok]

Hmmm, I don't call it a P6D in my signature below. The P6D is the Tripath based amp I built a few of several years ago (Pulse width modulation, 6 Watt, Demo).

On the capacitance, I'd check the Denon specs. I think they just say >100 Ohms. Maybe someone else has something to add concerning how one might optimize loading of a MC cartrige. My tendency is rather unimaginative: I read the data sheet and try to do what I read.

Leo