Phono stage revealing limitations of cartridge?


Hi,
I just purchased an Ear 834P for my system. This is my first experience with tubes. I hooked it up and I immediately noticed an improvement over the stock phono stage on my integrated. There was a much more three dimensional presentation. However, after listening for a few minutes, I realized the sound was very thin, light on bass, and the highs were bright and grating. Also, the output of the Ear is really high, so much so that the volume knob on my amp is almost all the way at the bottom and moving it very slightly results in a dramatic increase in volume. I'm wondering what is causing the bright sound. Here are the possibilities I've come up with:

1. The Ear 84P is just revealing the limitations of my cartridge which the stock phono stage had just smoothed over.

2. The stock tubes in it have gone bad. (I'm planning on trying out some Jan Philips 5751's on it to see if that lowers the gain a bit.)

3. The unit is defective/the person that modded it screwed something up.

4. I'm getting some very low level RF interference. You can't here it at all when music is playing, but if you turn it up all the way you can hear it. Perhaps this is causing the brightness.

5. The Ear and the Rotel integrated are a mismatch.

I've tried using a different cable from the phono to my integrated and that didn't change anything. I also tried using a different input on the amp. I tried both MM and MC to confirm that I am using MM.

Does anyone have any suggestions? I'd be really grateful if someone could help me get this sorted out. I know there's a lot of questions here, but I thought tubes would result in warmth, not brightness!!!

BTW, my system: VPI Scout/JMW-9, Sumiko Blue Point No. 2 (2.5 mV), Signal Cable Phono Cable, Ear 834P Deluxe Phono Stage (modded but w/ original tubes), Rotel 1062 Integrated Amp, Blue Jeans speaker cables, Infinity 3500 speakers (circa 1981)
sinisterporpoise68
Good to hear that you resolved your problems. My bet is that the tubes were going bad. But, it could also be the case that the 5751s are superior to the OEM tubes. Manufacturers must go with readily available tubes, in order to supply replacements to customers, even if there are superior alternatives. Readily available usually means in-production tubes.

With my Audionote amps, good vintage tubes were supplied by the manufacturer, but, these were somewhat common tubes (RCA 2a3s and RCA 5692s) and nowhere near the best possible tubes for these amps.

My phono stage uses 12AX7s too. I preferred the 5751s I tried with this phonostage over the manufacturer-supplied tubes, but I like Telefunken ECC83s and ECC803s even more. The ECC803 is, however, an extremely rare and expensive tube.
This must be my lucky day. I just put in a VPI Phono Cable. RF interference gone. No more radio through the turntable. It really needs a good breaking in though.
Hi all,
Got this figured out real quick when i opened the ear up to swap in new tubes: the tubes had been slightly dislodged during shipping. Either that or those stock tubes *really* sucked. I dropped in some Jan Phillips 5751's and this little box sings! I can't stop listening to records! Bass can be a little wooly at times but as the Ear warms up most of that gets corrected. This phono stage really sings and rocks. Music has never sounded so good in my house. Didn't even need to change the cartridge.

Thanks all for your generous help. Now to work on that RF...
The 834p has huge gain. Make a voltage divider with caddock metal film resitors and you will find things sound much better. The divider is very easy to make. Try 10k,5k,and 2k. The divider goes on the input of the line stage.

Tim
Hi all,

First off let me say thank you again to everyone who's responded. It's really generous of everyone to help me out with their suggestions, all of which are extremely helpful.

When I open up the Ear next week to change the tubes, I'll take a look at the settings and see if different loading settings help out at all.

For now, it's actually sounding pretty good today. I switched over to the Tape 2 input on the Rotel, which seems to have the least gain of any of the inputs--I had just assumed they would be all the same. I think that and letting it settle for a few days as well as leaving it on for extended periods to warm up have really made a difference. I'm getting some really decent bass now. The highs are still a bit bright, but it's definitely getting to a good place.

Everyone's suggestions have been so useful. I'm going to look into a new cartridge (the Dynavector 20X sounds like a good place to start), loading, tube choice, synergy, and possibly a new integrated. I really think I've gotten all I could out of the Blue Point and the Rotel and now that I've got the Scout and Ear it's time to move on in those departments. The Ear is definitely not as forgiving as the Rotel. I'll just need to find something that's a good match with the Scout, Ear, and my speakers!

I just tried ferrite clamps on the tonearm cable, but that didn't do anything about the RF. When I touch the tonearm cable or the tonearm, that's when the RF becomes really audible, but as long as I'm not touching them you can't hear a think at normal volumes. Maybe I should just ignore it? Larryi, thanks for the tip on the loading and the RF, I'll definitely look into this.
My first guess as to the source of your problem would be improper loading. Although the manufacturer of the cartridge may specify a particular loading, in reality, the proper loading differs from one phono stage to the next so one must experiment with different loading. When a cartridge is not loaded down enough (remember, the HIGHER the number, the lower the amount of loading--e.g., 47k is a very high number, so the cartridge is not being loaded down much), it will sound bright, edgy, sibilant and thin in the bass. Let's say you loaded the cartridge at 200 ohms with one phono stage, in a different stage, that same number may be way off the mark. So, experiment with loading before dumping the cartridge.

Choice of tubes can make a BIG difference so some experimentation there could yield a satisfactory result. If you are substituting the original tubes with 5751s to lower gain (your phono stage uses 12AX7s?) you could also get other sonic benefits because those vintage tubes sound pretty good. This substitution usually can be made without any problems, but, you might want to check with the manufacturer because it is not just gain that is different; the operating parameters are slightly different.

You also mentioned concern with lower output cartridges and RFI. If you have RFI concerns, you must be certain that all your interconnects carrying small signals are shielded cables. Also, I have found that cartridges that loading down a cartridge (lower number value for the loading resistor, e.g., 100 ohms or lower) dampens the top end response of the cartridge and significantly improves RFI rejection.
Are you using the mc setting or the mm setting? your cartridge output is exactly between what you need for either input, so I don't see how you could have an overload issue on the mm setting. A loading/impedance mismatch seems possible - you will be amazed how important that is. the transformers in the EAR834Pare are very much the weak link, especially if you've had good mods; they sound a little thin to me.
Think about querying AA member Flemke about how he resolved the same problems with his EAR.
I would make sure the cartridge is set up correctly first. Then get a test record to confirm. Your description sounds like it could be VTA that your old phonostage could not resolve.
I'm nervous that if I went with the low output Dynavector, the RF interference I'm getting would be amplified. If I understand correctly, if I used the high output Dynavector, I'd be able to use it in the MM section of the Ear, just like I'm using the Blue Point right now. I wouldn't have to change the loading or impedence, right? But I'd still be in a position in which I have too much gain.

Although, when I have turned on the MC section of the Ear, I haven't been getting the interference when I turn the volume up all the way... There are too many variables here!!

I'll have to wait to make a decision until I get the 5751 tubes with lower gain to see if that helps me at all.
Sns,
I did try some different inputs on the Rotel. I started off using the CD input and then tried the AUX and Tape 1 inputs last night. Those allowed much more play with the volume knob, so I'm fairly certain those have less gain than the CD input. It actually did help things a bit. I had a lot more control over the volume.

And thank you for your faith in my cartridge installing ability. It's not the alignment I worry about, it's the getting the clips on and off the cartridge that worries me. I really don't want to break the tonearm wire (did that with my music hall). But I do realize that's something I need to learn to do.

Thanks to everyone for their help! I really appreciate it.
Its hard to believe there is a gain issue, I ran my Blue Point Special with 50db of gain with no problem. On the other hand perhaps there is an issue with this amount of gain into that Rotel pre stage.
Sbank, the Dyna 20x comes in a high and low output version, 2.8mv and .3mv respectively. The Ear should handle the low output version just fine. Sinisterporpoise should get the low output version, this could very well solve the overload problem as well.
Sinister, you could also save yourself the hassle of having cartridges installed for you, learn to mount them yourself. Get something like the DB (I use) or many other fine ones and practice with your lower value cartridge, or buy a real cheapy for practice. Its not rocket science, just need a lot of patience and a steady hand, and some guts when you have a real expensive cartridge.
EAR/Cart mismatch, gain overload sounds likely. I agree that a Dyna 20x is a good choice; be careful it comes in a high & medium output versions. Other carts to think about include Denon 103r, Shelter 501, whatever you can afford in the ZYX line. If you have a friend who can setup let you try something with lower gain than the Blue Point, that will help you diagnose if this is the core issue. Cartridge loading also shouldn't be ignored!
I'm not going to debate the merits or not of the EAR, but say that before you think about selling it for anything, you should get a better handle on the root cause of your trouble. Experimenting with another phono stage and/or cart is best way.

Also, fine to power down and swap tubes just a couple minutes later. When they are cool enought to touch, you're fine. Ideally, gloves or a small towel will help you avoid getting oils from your fingers on the tubes; not the end of the world, but easily avoided.
I bet if you post about it, you can find other A-goners in your neighborhood willing to help you...Cheers,
Spencer
Did you try some of the other inputs on Rotel, some may have more gain/different impedences than others.
After much research, I decided to go with the Dynavector 20XL, installing today. You should take advantage of the MC input on the EAR, get a low output cartridge. Can't help you with the store.
I like to have gear plugged in and running for three days,before evaluating.It allows the connections and power supplies to "come up".
A pair of the original Mullards may be your cup-of-tea.
Thanks for all the help everyone. The Ear is connected to the AUX input of of the Rotel, not the phono input, so I'm alright there. From what everyone has said, a mismatch seems quite plausible. The Rotel is definitely on its way out. I was hoping I could get another year out of it, but maybe I can try to do something sooner.

In the meantime maybe I'll try out something from the Dynavector line. VPI seems to like the Dynavector 20X. Does anyone know a store in NYC that carries both VPI and Dynavector and could install the cartridge for me if I just brought in the arm?

Maybe a VPI phono cable would also be in order, since it uses the same wire as in the arm...
As reported in Stereophile's review, the 834p has very high gain of 49db in MM, 65db in MC. This in combination with a high-output cartridge like the BP, might be overloading your integrated. You could try cutting gain with a voltage divider comprised of two resistors per channel at the RCA connector.

I'm assuming that the EAR phono stage has been connected to a standard line-level input on the integrated & not to the phono input.
To maximize the sound you get from vinyl it is important that the 'chain' be compatible. Chain? Yes, the cartridge, table, arm wiring, interconnect, phono pre-amp. The phono pre-amp, especially all the EAR units present many problems - tube type/make and loading. EAR units are known to be bright, and not because of the tubes. The 'mod' movement has taken over here. In addition, you are now being told that only a new, expensive cartridge will be one of the solutions.

Dump the EAR and get a reasonably priced ARC phono pre amp in the used market.

Yes, your cartridge is likely the major culprit at this point. The Blue Point is notorious for lightweight bass, thin and analytical elsewhere.
I own a Blue Point Special, it too has lightweight bass and is somewhat thin elsewhere, and this should be better than the regular Blue Point.
Get something like a Dynavector 10x5, toss that Blue Point!
The EAR and Scout also deserve something better than the Rotel, something like the Cayin integrateds could fit your budget.
Thanks Thorman. I'm going to try out the Jan Philips 5751's when they arrive. I found a thread elsewhere in which someone recommended them. But if anyone else has any suggestions, I'd love to hear them.

On a positive note, I've left it on since I got home from work today and I just did a test with "Magattraction" by Girls Against Boys. I played this song last night and it was really grating (my wife had to cover her ears). But tonight after having the Ear on for 4 hours it sounded a lot better. Not quite there yet, but we both agreed it was better than last night. Perhaps it just needs a really strong warm up and break in.

By the way, how long should I leave it unplugged before opening it up to swap tubes? Do people just unplug it and swap and plug it right back in for some A/B testing? I was thinking I'd leave it unplugged for at least a day before doing that...
I'm unclear how you're routing the EAR to your Rotel. Are you saying that the Rotel has a phono stage and that you're plugging the EAR into that? If by chance that's the case, that's the problem. The EAR needs to go to a line input. Just checking. In any case, good luck and good listening.
I am only guessing but its possible that the person who modded it and sold it to you kept the "good tubes" for himself,leaving you with the stock tubes that were voiced for a stock unit..I wouldn't guess at what tubes to use..This is a very well regarded unit..More than likely you just need the proper tube tweek to help...I am sure some Audiogoners can help with proper tube choice...