Best MC capable Tube Preamp?

[Bob Clay]

Oy Vey - Ive got a little 60hz hum going on now. Ares going into Marantz 2325. Picking up a little hum when i turn the volume up. Ive checked the external grounds and everything seems to be fine. lord god i just want to enjoy my stereo without troubleshooting anything for only a day.

 

[Wildcat]

Standard advice probably applies--move things around, lift grounds here or there, etc. I fortunately have no hum in my setup (just a lot of hiss from the phono stage trying to boost the 0.12mv output of the ART7), but I've had it in the past.

 

[Bob Clay]

my turntable interconnects have the grounds attached for each channel. One is spade and the other is exposed (spade fell off before i purchased the unit second hand). Ground lug on the ares has the hole in the lug for insertion. So im putting one channel ground through the hole and the other spade with direct contact. Maybe i should spade the exposed ground and try that. Seems way to easy to be a solution but ill try.

 

[Wildcat]

As long as it is connected either way, I don't see it being much of a difference. I know from a few threads here and there that some have actually lifted the grounds in different places and found the hum reduced. In my setup, my interconnects are directional, where the grounding shield is attached only on one end of the interconnect, and the setup is dead quiet. Not saying that is the problem, but, that single-ended connecting of the shielding can help with ground loops to an extent.

With a low-output cart, though, you're "magnifying" a lot more through that much gain, so the hum you may not hear with a high-output cartridge might be manifesting itself once you add all that gain (through preamp and SUTs). Sometimes repositioning components helps with the hum.

The Rogue is known to be a quiet component, so, unless there was a bad tube in there, it shouldn't be the problem. But placement, interconnects, grounding, etc. can be an issue. It'll just take a little hunting to find it.

 

[Bob Clay]

^^jusr rearranged and reconnected and I’ll be damn it made a big difference. Thanks wildcat!

 

[mjw21a]

@mjw21a I'm enjoying the heck out of my ART7, but am not so much liking the Phonomena II+ phono stage with it--way too noisy. It was even noisy when I ran a Dynavector XX2. So rather than just stick an SUT in front of this thing, I'm taking a bigger move and upgrading the phono stage along with it. I figure I only live once.

I imagine you would. I'm running the ART9 currently and it's right up there with my Philips GP922 0.12mv LOMC.... Actually the Philips has a deeper sound stage so is a little better. The only issue with these ultra low output carts is that the required gain will amplify any hum that is present. Even more so than those with higher output.

I've finally bit the bullet and bought a Grado Statement Master 1, 40db separation and 10-60khz theoretically makes it my best cart. Should be interesting to try.

 

[Bob Clay]

I imagine you would. I'm running the ART9 currently and it's right up there with my Philips GP922 0.12mv LOMC.... Actually the Philips has a deeper sound stage so is a little better. The only issue with these ultra low output carts is that the required gain will amplify any hum that is present. Even more so than those with higher output.

I've finally bit the bullet and bought a Grado Statement Master 1, 40db separation and 10-60khz theoretically makes it my best cart. Should be interesting to try.

Wow great get!

 

[rothwellaudio]

@mjw21a I'm enjoying the heck out of my ART7, but am not so much liking the Phonomena II+ phono stage with it--way too noisy. It was even noisy when I ran a Dynavector XX2. So rather than just stick an SUT in front of this thing, I'm taking a bigger move and upgrading the phono stage along with it. I figure I only live once.

I fortunately have no hum in my setup (just a lot of hiss from the phono stage trying to boost the 0.12mv output of the ART7), but I've had it in the past.

The ART7 has a very low output which makes it difficult to get a good signal-to-noise ratio. Changing to another phonostage, even a much more expensive one, might not give you lower hiss. A SUT, either onboard as in the Rogue Audio phonostage or outboard, will give you less hiss than you have now. The downside is you might have to be careful where you site the SUT to minimise hum.

The only issue with these ultra low output carts is that the required gain will amplify any hum that is present.

Also, the low signal level means any hiss in the phonostage is more exposed. You need a very quiet phonostage with very low output cartridges.

 

[Wildcat]

The ART7 has a very low output which makes it difficult to get a good signal-to-noise ratio. Changing to another phonostage, even a much more expensive one, might not give you lower hiss. A SUT, either onboard as in the Rogue Audio phonostage or outboard, will give you less hiss than you have now. The downside is you might have to be careful where you site the SUT to minimise hum.

One reason I'd consider the Ares Magnum is that it has the Cinemag "Blue" step-up transformers built in. But otherwise, I'm going with the tubed phono stage that matches the rest of my equipment, combined with an outboard SUT. After this experience with the Phonomena (which sounds nice aside from the hiss), I'm quite convinced now that the correct way to do an MC cart is with an SUT.

 

[twiiii]

You are tying your hands behind your back saying best and $500.00 dollars. For that budget stick with SS. Its not like hold days, 60's, when you could by a Marantz 7C, Mcintosh C-22 or Citation pre-amp for under $300.00. Good luck.

 

[zaskarx]

I just went through this same exercise and ended up buying an open box Project Tubebox DS 2 for $550. It's in the mail so I havent listened to it yet.

From what I understand, it is incredibly difficult to make a full tube-based MC preamp due the large amount of gain required. Most of the designs are hybrid, with preamps like the Project tube box series using tubes for the output stages. Here are the options I found, all of which seem to be well liked:

-Project tube box series, there are some minor variations between models but all apparently sound similar. The Tube Box DS is on closeout and can be had for $400.

-Used Jolida JD9

-Used Parks Budgie, Parks no longer makes this model but it receives universal high praise.

Good luck!

 

[rothwellaudio]

From what I understand, it is incredibly difficult to make a full tube-based MC preamp due the large amount of gain required. Most of the designs are hybrid...

Yes, making an all-tube MC phonostage is very difficult to do successfully. It isn't so much the gain required which is the problem - it's easy to add another tube to get more gain - it's getting a good signal-to-noise ratio with low output cartridges which is so difficult. There have been designs which use several tubes in parallel for the first stage to get the noise down, but they're very expensive to implement, they can get noisier with age, and they're not particularly low-noise anyway.
There are quite a few "tube" phonostages which use transistors or op-amps at the front end to give them MC capability, but they're certainly not "all tube" and won't satisfy tube purists. An onboard or outboard SUT is really the only practical way forward to make a tube phonostage MC compatible.

 

[zaskarx]

Yes, making an all-tube MC phonostage is very difficult to do successfully. It isn't so much the gain required which is the problem - it's easy to add another tube to get more gain - it's getting a good signal-to-noise ratio with low output cartridges which is so difficult. There have been designs which use several tubes in parallel for the first stage to get the noise down, but they're very expensive to implement, they can get noisier with age, and they're not particularly low-noise anyway.
There are quite a few "tube" phonostages which use transistors or op-amps at the front end to give them MC capability, but they're certainly not "all tube" and won't satisfy tube purists. An onboard or outboard SUT is really the only practical way forward to make a tube phonostage MC compatible.

Very interesting and concise explanation, thank you.

 

[KB007]

Yup, it's true, for the most part. Both of my better phono stages (Manley Steelhead and ARC Ref PH2SE) have transformers in the MC section one way or another. Manley design their own "autoxformers" ot exactly sure how that works, but it does. The ARC also has a xformer in it's signal path for MC.
Having said that, I would expect each of those companies to have done some serious testing to figure out not only the best xformers for the job, but also what ever else makes sense to have in the circuit. I stroingly doubt they just built an MM phono stage and added a couple of xformers.
I also own an older Acoustech PH-1. Initially it sounded very good, but as the rest of my system got upgraded it started to struggle to keep up as an MC stage. Not long ago, I picked up a Rothwell MC1 and using it thru the Acoustech on MM setting worked far better with my current system.