New toys: Parasound JC3 phono preamp & Lyra Delos cartridge

Wouldn't returning the JC3 be the easiest solution? Plenty of other great options for that money.

 

Maybe. It is certainly something I'm considering. I think moving the phono cartridge sideways is an equally good option.

I look at the cartridges I've liked over the past thirty-five years and they are either moving magnets, which are not an issue. or very low output moving coils, with around .3mV of output. Those would be fine with the JC3.

My biggest mistake may have been buying what I consider a medium output moving coil.

This is all speculation, though, until the attenuators arrive and I can confirm the cartridge is not defective. They should be here today.

 

You say attenuator and everyone goes nuts about degrading the sound quality, but they sure are an inexpensive tool when you are trying to sort an issue like this. They have been for me.

 

LOL. Yes!

Attenuators are all over our stereo gear. You could easily have 3-5 attenuators in the signal path already, with volume controls, input level adjustments and subwoofer level controls.

The attenuators I'm getting in today are just a step in the process. They will tell me if the problem is gain. I know the Harrison Labs gear. It is cheap but effective. I'll never be satisfied with these attenuators in the circuit in the long run.

If I go attenuation, I'm going to make something better, something at will sound good. I'm not considering anything beyond a basic resistive circuit. This is not tough. I don't want anything variable. It would be a box with resistors and a four RCA jacks. Yes, I'd used the best resistors I can get my hands on but designing it could be done by a first year electrical engineering student. I find it hard to believe 10-12 dB of attenuation can't be achieved without degrading the sound.

Plus, and this is a huge plus, it would be a gas. I got into this hobby making Knight Kit walkie-talkies when I was 10. By high school, I had built an Allied short wave radio and put an antenna on my house. Getting out the silver solder, and the iron I have reserved for it, is what I like to do. Building the box would also allow me to meet someone I mentioned upthread, a local EE independent contractor who loves an analog challenge. It would be cool to work with him. He would design the circuit.

We aren't talking a lot of money and projects like this are what makes this hobby enjoyable. It's creative. It's fun.

 

The parts needed to check out the Lyra Delos cartridge and gain issues with the JC3 arrived late last week. Today I had time to try them out.

Mounting the Delos back onto my VPI, using the VPI's alignment gauge, I quickly discovered that, yes, the issue is gain. Putting the Harrison Labs 12dB attenuators between the JC3 and my Plinius amp solved 70% of my problem. The extreme hash in the high end was gone. Adding 400pF of capacitance using the DB Systems capacitance loading jumpers smoothed out the high end even further. There was more depth, especially in the center image, than before.

Still, the sound wasn't super. It certainly wasn't magical. In many respects, I preferred the sound I got with my temporary solution, the mid 1980's Koetsu Black I've been using the last few days.

It's hard to say why the "wowsah" factor was missing today. It could be in the cartridge. I'm not sure I trust this particular Delos cartridge. It could be in the two adaptors now in the circuit. I am listening through a cheese-ball Y cord with the DB Systems device and $25 Harrison Labs attenuators. We aren't talking audiophile quality here. There are too many variables here to blame the less than stellar sound on any one cause.

I've made two decisions so far:

1. I'm keeping the JC3. I really like it a lot after listening to it through a compatible cartridge. Very low output moving coils are plentiful and often my preferred type. I'm not married to the Plinius, and as my problem revolves around an input overload of its line stage, the amp could be changed (I have a Levinson ML-7A in my basement and I might pull it out to see if the problem goes away with it. It was known for having a ton of headroom in its line stage.). I was planning on replacing the Plinius next, anyway, just not until 2015 or 2016. Now that might come sooner.
2. I am going to ask AudioQuest, the current distributor of the Lyra cartridges, to check out the Delos. I am gun shy over its performance. Plus I don't want to go through extraordinary lengths to make this particular cartridge work if it might be defective. Getting it re-evaluated would be worth it for my peace of mind alone.

Beyond those steps, I see a few options:

1. I could sell the Delos and use one of the cartridges I have lying around. This is my least favorite option. I don't think it's likely.
2. I've talked to Galen Carol this morning and we could work out a deal for my returning the Delos toward a special low output version of the Lyra Kleos. At 0.26mV output, that would solve the problem.
3. I can work with the local analog-friendly electrical engineer mentioned upthread to come up with an audiophile grade 12-14 dB attenuator. I've spent some time this last weekend on diyaudio.com and the Parts Connexion investigating audiophile grade resistors.

I don't know what I'm going to do yet.

 

The Koetsu Black is a pretty nice cartridge to have just lying around! I would stick with that for now if I were you and see how you feel in a couple of months.

 

Personally, I would give that one some serious thought as well. IMO, the JC3 still has too much gain to be an ideal match with the low output Kleos (I'd be looking at cartridges with about .15 mV output and not more than .20 mV. On top of that the Kleos has a very low internal impedance of 2.7 ohms and may well want to be loaded lower than the 100 ohm fixed loading that your JC3 has.

That's just me though-I would not be keen on having the better part of $5K tied up in cartridge/phono stage that were much less than being extremely complimentary toward each other.

 

And here I thought I'd get grief for having a Levinson ML-7A sitting around unused, in a box in my basement. I guess I shouldn't bring up the Nakamichi Dragon-CT turntable that's down there, too, should I?

You do make a good point. In any case, I'm going to go back the Koetsu while I sort out my difficulties here. It may end up being the permanent solution. I just don't know yet.

Maybe, but remember I've found the Koetsu Black with 0.4mV of output very satisfactory in my system. The 2dB gain acceptability window you've found in the past may be a bit larger than that for me. FWIW, Galen told me this morning of a demo system they have in the store with a JC3+ and a Clearaudio cartridge with 0.7mV of output. He says that sounds golden. I'm sure it does.

As for loading, with the low output Kleos, Lyra specs a load impedance of 86.6 to 47k Ω.

 

I just ordered a new JC3+. It will be on its way to me tomorrow and probably arrive Saturday. This is replacing a Fosgate Signature v2.

I will be using it with a Clearaudio Talisman v2, which has .7mV at 5cm/s output. I am a little concerned that the 64db gain is high, but I have 30 days to decide to keep or return it. I'll need half that time just to burn it in. I had to go for the plus version because my Talisman loads at 400-500Ω. It would sound very boring and timid at 100Ω.

 

Glad you have it solved. I see people who would seem to have gain issues that hear no gain issues. Michael Yee has said on occasion that he believes too much gain is one of the major unrecognized issues in many systems.

The lower output version seems like the way to go. Galen is a great guy to deal with. He has sent out gear for me to listen to in my system when the shop 4 blocks down the street couldn’t be bothered.

Those attenuators are not made of great materials. If you open one, is has surface mount components inside, and could very well be causing any problems that seem to remain.

There are gain calculators out there people.

 

jupiterboy, I don't know if I'd use the word "solved" quite yet. Certainly I feel in more control of the situation and that is very good. But as to what will be the final outcome here? Difficult to see. Always in motion is the future.

The Delos is back at Audioquest for another run through QC. First let's see what they say.

Meanwhile, I have the Koetsu pretty well dialed in. It took a Lofgren B geometry setting, tracking at 2.4 grams, and some fiddling about to make it happen. It's been years since I've used this much anti-skate on a cartridge. I remember what I didn't like about the Koetsu Black back in 1983: it's a pretty poor tracker. But the cartridge does sound very nice, with a great bass, super dynamics and wonderful layering of depth. I'm happy for now.

I'll keep you informed. If Vegas is offering odds, I'd bet that I will have a different cartridge than the Delos in a month.

 

I like Lofgren B, but it never does as well on the test tracks. It sounds really good with more separation and a larger stereo image on the best records though, and I keep trying it. I suspect I need a perfect match with arm and cart to pull it off.

 

Great thread, tons of insight and practical knowledge that many would never come across anywhere else. I love these forums. Thanks to all for their input, this is very enlightening. And a big congrats to "ggergm" on his new additions, unfortunate that it is a bit of a rocky road to your own personal audio nirvana, but for us out here in the ether reading about your experience, it has been a very revealing process.
Cheers!
–R

 

Interesting weekend. I received emails from Jonathan Carr, the designer of my Delos cartridge, and Stig Bjorge, the head of Lyra.

First, I must clean up a mess I made. I completely mis-read the manual that came with my cartridge. Upthread I said:

No, that is not true. Here is part of Jonathan Carr's email to me:

"The proper way to interpret the Delos's manual is "if you use X value
of capacitance, you will likely need to use Y value of resistance (or
lower) to squash the ultrasonic resonant peak that the capacitance is
creating'

"The Delos should be run with as little capacitance as your tonearm cable
and phono stage allow. The lower the capacitance between cartridge and
phono stage, the higher you can go with the loading resistance values,
and this should give you better dynamics and resolution."​

I apologize to Jonathan, Stig and everyone for getting things exactly backwards. It's not that if you are hooked up into a low impedance load, then you have to have a lot of capacitance. Instead, it's that if you have a lot of capacitance in the system, then you have to use it with a low impedance load. My error completely. I am sorry for it.

So to make it totally clear:

"The Delos should be run with as little capacitance as your tonearm cable and phono stage allow."
- Jonathan Carr

That's enough for now. I'll write about the rest of the emails later. For now, just say sayonara to my cartridge. It's on its way to Japan.

 

Just curious, was there something that you didn't like in the Fosgate? I recently compared the JC3 (old version) with the Fosgate for a second system that I am assembling and I prefered the Fosgate. JC3 sounded too clinical.

 

http://forums.stevehoffman.tv/threads/parasound-jc-3-review.341720/#post-10056651

 

As mentioned elsewhere, my Fosgate was great, but developed a service issue.

In the meantime I cancelled my JC3+ order. I am getting a Herron Audio VTPH-2 instead. I really wanted to stay with tubes for the phonostage after the Fosgate. I would have gotten an Aesthetix Rhea or an Octave Phonomodule but I just couldn't stretch my budget farther than the Herron (which I understand is outstanding). The Herron is also made locally so I see that as an added benefit.

 

Thanks, good choice with the VTPH-2

 

Jonathan Carr sent me an email on Saturday. It was long and detailed, as he was obviously interested and concerned about my problem with the Delos.

Let's just pause here to appreciate how great this is. I have the designer of my cartridge write to ask me about the problem I'm having. It says two things: one, he is concerned about the customer beyond all measure, and two, Lyra doesn't have many complaints. I am blown away, appreciative and impressed. Things like this have happened before to me in 30 years of selling hi-fi but it is rare and impressive each time. Thank you, Jonathan Carr, for your concern.

He had read this thread. I assumed it was because I had referenced this thread in emails to the Customer Service department at Audioquest, the US distributor of Lyra.

Beyond asking me some specific questions about my situation and what I'd tried to do to solve the problem, Jonathan agrees with the consensus here. My problem is a gain issue, with a combination of a lot of gain from the JC3, a 0.6mV output of the Delos and low input level headroom on my Plinius. It's an unfortunate combination. It was fun to read his email. He was obviously writing it as he was reading the thread. He figured out the problem way before I did and our general agreement here that it was too much gain only reinforced his diagnosis.

Jonathan also agrees that attenuators between the phono stage and my amp is the solution.

From here it only gets better. Next the head of Lyra sent me an email. Stig Bjorge had been CC'd by Jonathan and wanted to mention a possible solution in the Rothwell attenuators. A friend of his had tried them with a preamp/power amp mismatch and they had solved that problem.

Thank you, Stig Bjorge, for your interest in my situation. This is taking customer service to a new level.

Both Stig and Jonathan commented that a DIY attenuation solution wouldn't be that hard to do. I agree. I have been studying up and I'm confident I can build an attenuator that will be transparent and better sounding than either the ones from Harrison Labs or the Rothwells. Much more on that in later posts. In fact, I can tell you right now that this thread will morph into a DIY attenuation project one.

Both Jonathan and Stig ended their emails saying how Lyra would be glad to evaluate my cartridge and take care of my concerns. Stig went even further. In his email, he told me that Lyra would "inspect, re-adjust and re-voice your Delos as soon as it arrives at Lyra, and then return it quickly via Audioquest."

Holy buckets, I'm going to end up with a bench queen.

For those of you unfamiliar with the term, a bench queen is a piece that has been tweaked by a service tech to perfection. I first ran into the phrase in reference to review samples. In the 1970s and '80s, it was alleged that favorable reviews in stereo magazines were more likely because they pieces under evaluation were all bench queens. You and I own stuff that's raw out of the box. Reviewers get bench queens. While the allegation never stuck, I've owned some bench queens. They always sound better.

When I get my Delos back, it will be a bench queen.

How great is that?

Thank you, Lyra.

 

With my Lyra Delos cartridge on a working vacation to Japan, getting evaluated and tweaked to its best possible performance, it's time to figure out what I want to do for attenuation. I want to build the attenuators now so that they will be ready when the cartridge returns.

(For those of you new to this thread, I have a component mismatch between my Plinius 9200 integrated amp, a Parasound JC3 and the Delos. I get too much gain from the Delos/JC3 combo which is overloading the input on the Plinius. I want to build some audiophile quality attenuators to solve the problem.)

I'm not an electrical engineer. I know there are a few on this board. Many more posters play one on the Internet. If I am missing something in the following design, please let me know. I want to buy the parts for my attenuator this week but before that, I will wait for your advice.

The first question is where does the attenuator go? Should it be between the Delos and the JC3 or between the JC3 and the Plinius? I am choosing the latter. The voltages are so incredibly low coming out of the cartridge, any problems or irregularities in the attenuator could have a dramatic effect on the sound if I put it there. The voltage coming out of the JC3 is 2,500 times higher than that coming out of the cartridge. That should forgive any slight permutations in the attenuator.

Putting the attenuator after the JC3 also allows me to take advantage of a unique situation I have regarding the input and output impedances of my gear. As measured by Stereophile, the JC3 has an unusually low output impedance of 100 Ω. My Plinius is spec'd with an unusually high 47K Ω impedance across all inputs. One always wants to go from low to high impedance. By the book, an input impedance that is 20 times higher than the output impedance is considered ideal. If I build an attenuator with an impedance of somewhere around 2,000 to 2,200 Ω, I can get a 1:20 ratio going from the JC3 to the attenuator and another 1:20 ratio out of the attenuator to the Plinius, or approximately so. Close enough for this old stereo salesman.

To make this happen, I need more than a basic L-pad attenuator, which uses two resistors. I need an attenuator that shows a constant impedance across the device. I need a three resistor T-pad circuit.



If R1 and R2 are the same value, a T-pad will have a constant impedance.

Another question is how much attenuation do I want? I bought some cheap-ass attenuators which I knew wouldn't be good enough in the long run but allowed me to verify that, yes, the problem is too much gain. Those are -12 dB devices. I have so much line gain in the Plinius, I want to attenuate the signal a bit more than that. I've elected to build -14 dB attenuators. (Actually, in the long run, I think I'll build a second -7 dB attenuator for use with cartridges which have a little lower output than the Delos.)

There are numerous attenuation calculators on the Internet. I used this one (it is also a H-pad attenuator, which works for balanced connections). I moved around the input/output impedance figure to end up with resistor values that I can actually buy. I will need to put two resistors in series to get to these values but that's no big challenge. Plugging into the calculator an input/output impedance of 2065 Ω and a -14dB of attenuation, I end up with the following resistance. The actual values of the resistors I will buy is also shown. The difference between the calculator and reality is less than the 1% tolerance spec of the resistors themselves, which is all I can ask for.



I am considering using Riken ½ watt resistors. I can get them from Parts Connextion. There is a 45 page thread over on DIYAudio just about the sound of resistors. Wowsah. Scanning through it, it seems like Riken resistors are well liked for their sound even though they're a little expensive. Rikens are $4-5 each but with this kind of project, do I really want to scrimp by using cheaper, 5% tolerance generic resistors? I don't think so.

I'll write more about the physical construction of the attenuator tomorrow. As for now, does anybody object to what I'm considering here? Am I making any mistakes? If so, please write.

 

That's very good service. Glad they are taking care of you.

 

I spend much of yesterday drawing my attenuation circuit and sourcing the parts.



I am going to build a true dual mono design, with the left and right channels each in their own project box. I can buy small aluminum boxes from Parts Express. Using Cardas RCA plugs and wires I found at Parts ConneXion, I'm going to bring a pigtail straight into the box, using a strain relief to take the load. By connecting the shield from the pigtail to the box, the aluminum box will protect the components and wires inside from stray RF. I'll connect the shield on the other end of the pigtail directly to the RCA plug. I'll use RCA jacks mounted to the box for its output. These parts amount to about a third of the total cost of the attenuators.

In the drawing, each of the black dots are solder posts. They'll be mounted directly to the boxes through insulators.

The ½ watt Riken resistors are only a quarter of the attenuators' cost even though they are a bit expensive. Here you can see the actual values of the resistors I plan on using.

The whole thing will cost about $200, double what I was expecting. The attenuators could be built for less than $100 and still use Riken resistors but I'd have to make many changes. Instead of Cardas plugs, jacks and wires, I'd use generic ones. I'd eliminate most of the solder posts, instead just wrapping wires together, with only solder to keep them in place. Everything would be in one box, which would compromise the integrity of the dual mono design of the JC3. If I'm going to all this trouble, I see no sense in scrimping. I'll pay the extra $100 gladly.

As before, if any of you electrical geniuses see anything wrong here, please let me know.

 

I for one would have moved on to more appropriate combination of equipment after spending the amount of time and money you have into this (you would think for the money the JC3 would have a bit more options).

Or at the very least picked up an el-cheapo attenuator to see if it made a difference before I spent an additional $200 + time and effort to create something that you don't even know 100% for sure that it's going to solve all your problems. If it's an attenuator problem, even an inexpensive one should straighten things out, then you could build a better one with higher quality components once you find out the cheap one works.

I guess it's a good learning experience, but if I doesn't work out ... all that effort and money would go to waste. I have to say ... I admire your tenacity and I hope it all comes together and you get a kick ass setup!

 

You and I think alike, beowulf. Upthread I mentioned I tried a Harrison Labs -12dB attenuators in my system. I had experience with these in the past and knew they were cheap but effective. Cutting the gain by 12dB solved the overload problem but the poor quality of the Harrison Labs pieces didn't let the detail and beauty of my system come through. That's why I'm building my own attenuators.

While certainly the desire to learn and grow is part of my motivation, it's more than that. This is what I do. It is what I've always done. My interest in sound and electronics started with building kits. Growing up, I'd get the new Heathkit and Knight Kit catalogs and see gear I'd want to build. Sometime in the 1980s, stereos went from being a play thing to an appliance. I hate that.

This desire to create my own stereos is what has always drawn me to car audio. I love designing and building high end car stereo systems. It's creative. I make my own passive crossovers for car stereos. They allow me to adapt the output of speaker drivers to the particularities of my vehicle. I have a box of miscellaneous cheap caps, coils and resistors. I build a crossover first on a breadboard, pulling over to the side of the road when I hear problems in order to swap out components. When I get the system sounding like I want it to, I then order high quality parts from Madisound and solder together the final crossover.

It's been fascinating spending the last week over on DIYAudio.com. You think I may be going down the wrong path, beowulf? You should see those folks. My circuit is child's play compared to what posters are building there. My kind of people. In fact, this morning I'm starting my first thread there, checking with them that I'm on solid ground with my attenuator circuit. I'll let you know if they come up with any changes.

Thank you for the encouragement. I'm sure it will. And if not? I've been there before. In 1989 I spend days building elaborate fiberglass enclosures for a pair of mid bass speakers inside the rear wheel wells of a Honda Accord coupe. The mid basses were great Audax drivers, driven by outstanding a/d/s/ amps with an Audio Control electronic crossover. After I got the car put back together, I realized that the system sounded better with the mid basses turned off. I learned the lesson that less is more when it comes to speaker drivers and great car audio. Never made that mistake again.

I did like the center channel I installed in that car. Until I used time alignment on later systems, it was the only way I could get a tight center image.

You never know until you try.

 

My Lyra Delos cartridge is back from its trip to Japan!

It arrived on Saturday. As a quick summary, it went there for evaluation and realignment. I now have something very unique, a cartridge that's been tweaked up by the factory after it's been broken in.

Recently this thread has been about attenuating the output of my Parasound JC3 phono stage so that it doesn't overload in the input of my Plinius 9200 integrated amp. The final shipment of parts for my attenuator arrived a week ago so I better get it built.

There are in fact three upcoming topics for this thread:

1. Constructing the attenuator
2. Does the attenuator solve my problem with the JC3?
3. How much if any does the attenuator otherwise affect my sound?

This next few posts will be about the first topic. I will have to break up building the attenuator into a four posts as I have too many pictures for the board's limits.

Let's jump right to the finished product. Here is one channel of the completed attenuator. While the values of two of the individual resistors changed from upthread because I had to substitute parts, the overall resistance from the attenuation calculator has remained the same.



Here are all the parts I used. They came from Parts Express, Parts Connexion and Angela Instruments. Total cost was $180.



Top row: Riken resistors (Parts Connexion and Angela) / forged aluminum boxes (Parts Express)
Middle row: white Cardas hook up wire (Parts Connexion) / Cardas male RCA plugs and female RCA jacks (Parts Connexion) /

solder posts (Angela) / strain relief (Parts Express) / screws for covers for the aluminum boxes​

Bottom row: blue Cardas hook up wire (Parts Connexion) / green Connex hook up wire (Parts Connexion) /

Cardas shielded cable with two inner conductors (Parts Connexion)​

The box you saw was the first one I built. It took a number of hours but there was the learning curve. The second one took only an hour and a quarter. It's of it that I took the most pictures.

I started by soldered the RCA plugs onto the Cardas shielded cable. I ran into my first two problems.

One, the Cardas wire totally rejected my soldering attempts. It wouldn't accept the silver solder I was using. Fortunately I had some silver dip, an acidic liquid used to polish silverware, around the house. Metal is metal so I stuck the trimmed ends of the bare Cardas wire in the dip for a minute. It then would accept solder although I had to use a lot of heat. I'm not sure I'd ever use the Cardas wire again.

At times I had to use my father's ancient soldering iron, made for soldering metal, not electronics. Now this is a soldering iron!



The second problem was the Cardas plugs themselves. I both loved them and hated them. They are solid metal (loved), not the stamped and bent tin that makes up most RCA plugs. Because of that, they, too, needed a lot of heat (hated). I also wasn't wild about the neutral/shield connection. It's just a slot in the plug. By tinning both the wire and the plug first and having Dad's iron come to the rescue, I could make a good connection but I don't know what I would have done if I had only a pencil iron. While not pretty, the plugs and the connections are solid.



continued in next post