How much noise on your tube phono preamp?

I have an EAR 834 clone, and it is pretty quiet with a regular 5mV output MM cartridge. I would like to use an old Excel quadrophonic cartridge with a nice Shibata needle on it, but it only gives out 2mV and the noise increases by about the same magnitude (2.5X, app.).

I am wanting to buy a SUT, to use a Denon DL-300 or other LOMCs with it, but I wish I could know for certain that the SUT will lessen the noise as it receives a stepped up voltage similar to a regular 5mV output cartridge, or if the SUT will simply make noise matters worse.

Any other users of a similar EAR834 clone, who use a cartridge with less output than mV? How are your noise and hum levels?

 

Doesn't it have something like 53dB gain? Should be plenty for a 2mV cartridge, but maybe you need quieter tubes. The trouble is that it only uses 3 dual-triodes to handle both sides, so none of them are paralleled to lower the noise, and you need to use really quiet tubes, especially on the input. What tubes are you using now?

My CJ Premier 15 has about that same gain (without the 1:6 Partridge SUTs I have on the inputs), and is very quiet, but it uses 4 dual-triodes in the input section, so four sections in parallel on each side, and then two more dual-triodes for the second stage (so two in parallel on each side), then a couple single section followers for the output.

But you are asking about something like a 1:3 SUT? I know that Lundahl did introduce something like that a few years ago to better handle high output MC carts, or low output carts for preamps without quite enough gain, looks like K&K lists them at $175 each ... https://www.lundahltransformers.com/wp-content/uploads/datasheets/1963.pdf

 

My EAR clone apparently has 48 dB of gain. It is acceptably quiet with a 5mV output MM, but the hum (not high tube white noise) becomes quite audible with the gain set louder on my preamp, with the 2mV Shibata stylus.

I am using 3 Bogen/Mullard tubes (matching is unnecessary on this design, but I have three matching ones, so I am using them). I have also tried 2 JJs, an ELectrohome, 2 Brimars, a 12AT7 as V3 (buffer), and perhaps a few more. No change in the hum.

I have also gone over the solder joints, but this has not made a difference either. I am almost ready to take it to my local tube repair shop but since I got this for free (traded for a pair of free, unused speakers), and it only costs around $250 USD new, I don't want to spend a whole lot getting it worked on. Especially because I am wondering if this is simply the limitation of this EAR 834 design.

Can better caps and resistors really make that much of a difference?

What is this about AC "ripple" getting into the DC?

 

I don't know which "clone" you have, some of them are electrical and mechanical clones that look the same as the 834p, while some are just based on the circuit schematic and bear little physical resemblance to the original. The original is pretty high gain and pretty quiet too, owing I assume to the toroid transformer and good layout practices. Obviously some of the "clones" use neither.

But I obviously thought you were referring to tube noise, not hum, so don't really have anything to add for that issue, sorry. It could be that it doesn't use large enough filter capacitors for the current draw, so too much AC ripple on the DC power to the tubes. There are quite a few build threads on other sites like the Lenco forum for some of the Chinese 834p kit "clones", maybe they could help.

 

I use a Manley "Steelhead" as my phono preamp / preamp (all tubes). Zero noise with this set up. No need for an additional preamp...as I only listen to Vinyl.

 

Bellari VP-130. No noise
Vincent PHO-701. Dead quiet.

 

Nice preamp, they really make solid gear. Technically speaking, not quite all tubes since they use FET-triode gain stages, but close enough among music lovers

 

Isn’t 48 dB still a little high for a MM cart...?

 

I'm using an Excel ES-70EX4 Shibata at 2mV output into it, and it sounds excellent.

 

It would see a little high to me, but might work okay depending on system specifics. I don't know OP's gear. KAB calculator recommends 44dB but tends to be on the conservative side IME.

In general I'd be suspicious of any "clone" product that uses off brand or potentially counterfeit parts, or alters the original design. Buying another product to a use a band-aid for the "clone" preamp seems misguided to me.

 

I "get" the "feeling" you don't "like" "clones".

 

It depends how they are made but not something I would buy for myself. Take that thing to a tech and don't be surprised if many of the components inside fail to meet the spec printed on them.

 

Nor would I, before I got this thing. Traded it for a free pair of unused speakers, so it cost me nothing. Amazed, quite frankly, at how captivating the sound is. I have barely listened to my Benz Micro PP1 preamp since getting it.

This is why I am curious how much this thing can be improved. I am thinking of taking it to my tube tech, but I am having fun with a soldering iron right now, going over the joints. I might simply start replacing caps, especially the coupling caps, as my gut says this is the cause of the low level hum. Wish I didn't sell an old oscilloscope to my tech now!

 

The way I look at these things is you are basically buying something that's like a kit. You're on your own as far as troubleshooting goes or figuring out what's wrong. I've seen people take them apart and use nothing but the PCB and enclosure when they are done. To me it would be better to just get a kit from a reliable source where you know the parts will be decent quality. I'd imagine by the time you order an entirely new set of parts from Mouser or whatever you've exceeded the FMV of the unit.

 

I see that for that output, but a 2m black on that and it would probably be too much...

 

48dB seemed high to me, too, on paper anyways.
But a regular 5mV cartridge sounds great on the phono pre.

 

Problem fixed!

The previous owner of this Zero Zone 834 clone attached he +/- of the third pair of leads from the power supply board to the circuit board in the wrong polarity! Not sure what this third pair is/does, but the low level hum is gone! Pretty damn quiet now!

And I have just received a K&K Step Up Transformer using 2 Lundahl LL9226 transformers, and it sounds excellent with a Denon DL-300 low output moving coil cartridge!

My silly dream of having the entire signal chain with tube amplification is realized!

Well, almost - my Velodyne sub and two Tannoy woofers acting as subs, are all amplified by SS units. But this seems like the true "best of both worlds" scenario!

I can wholeheartedly recommend the Zero Zone 834 tube phono preamplifier. It is one excellent unit for the money. I think I am going to sell my Benz Micro PP1.

 

That's fantastic.
Bet you sure feel good right about now.
This hobby can certainly have highs and lows.
The elimination of hum and noise from our systems is certain to take you deeper into the zone while listening.
So I can almost feel your satisfaction.
You know satisfaction has been known to revive some pretty dead cats in its time.
This cat for one.
GREAT JOB!

 

Probably the heaters.

 

You know it!

My special galfriend is into hifi (she has an Empire 66 cartridge with GENUINE stylus on her turntable, fer chrissakes!), but she doesn't get as excited about something like this as youz guyz. Times like this I LOVE this site!

Thanks for all the help and support! Just finished my orchestra videotaping session, now blasting some Stravinsky, with beer and pie! <3

 

Would wrong polarity at the heaters cause "AC ripple in the DC", as someone somewhere surmised?

 

Well, if connected wrong, I think the ripple on the heaters would be out of phase with the ripple on B+ power so would cause the hum, but I'm not a tube amp designer so may be wrong.