Yamaha CX-1 Thread

I also have an "issue" in the low bass it seems. I bought two very high quality Viablue Y adapters, to be able to connect my active subwoofer on the single stereo output (my usual preamp has two outputs + a subwoofer output...)
Well I'm disappointed. Low bass seems weak. Normally I have to set the volume very low on the sub, otherwise it overpowers everything, it's a very potent Focal Electra SW900A... with the Yam preamp Have to set the sub way higher and it's still a bit anemic. I don't know if the Viable adapters are the cause (or if the output is unable to drive two devices? But being very low impedance at 47ohms, it should have no issue driving two pairs of cables and two amps) or if the preamp's caps are really dried out :-/

Have you tried just hooking up the subwoofer directly to the pre-out? Any difference?
 
I also have an "issue" in the low bass it seems. I bought two very high quality Viablue Y adapters, to be able to connect my active subwoofer on the single stereo output (my usual preamp has two outputs + a subwoofer output...)
Well I'm disappointed. Low bass seems weak. Normally I have to set the volume very low on the sub, otherwise it overpowers everything, it's a very potent Focal Electra SW900A... with the Yam preamp Have to set the sub way higher and it's still a bit anemic. I don't know if the Viable adapters are the cause (or if the output is unable to drive two devices? But being very low impedance at 47ohms, it should have no issue driving two pairs of cables and two amps) or if the preamp's caps are really dried out :-/

I don't have the experience with splitting the signal like that to be able to give a good answer, but IIRC the CX-1 has a maximum output of 7v. I would think that that's enough to be able to supply both a power amp and sub. Have you tried hanging the y-cables and sub on your other pre-amp to compare? (rather than using the 2nd output)

Cheers,
James
 
Pretty sure those come in the "In case of emergency, break glass" type containers. :biggrin:

No need to break the glass. I have plenty of bottle openers and never leave home without one and a Leatherman Wave. But this is Munich. You're never more than a 10 minute walk from a beer. :)

Cheers,
James
 
Have you been there long enough to remember "the Deutsche Mark" ? I think they went to the Euro in 1999.
 
The sub output of our usual pre is maybe much higher than the normal output of the Yam ?
If it's only a level issue, IMO it's not an issue at all.
 
Have you been there long enough to remember "the Deutsche Mark" ? I think they went to the Euro in 1999.

Yes. I got here in '97, so had a few years to get used to the DM. Going to the Euro was actually nice from my POV, it was like going back to the Dollar, it was easier to know how much I was really spending on something.

Looking at a bolt and being able to say "that's 13mm", or picking up a piece of sheet metal and knowing "that's about 0.8mm thick", well that took a lot longer to re-calibrate my fingertips, elbows and eyes.

Cheers,
James
 
Just an FYI if you ever want to seek a decent replacement for the JRC 2068's with something that is through-hole DIP package, that sounds good is the OP275 from AD. It doesn't quite match the performance of the OPA-1602 (which matches the current requirements, and where the OPA-1612 can draw too much current if the supply isn't capable) however, there isn't a real good choice to properly decouple SOIC on riser boards, so the advantages to be found in noise performance is actually lost. So i you are looking for something that sounds almost equal to the OPA-1602 in DIP then I can attest to the OP275, and it's performance is much more appealing than listening to the NJM2068.

Interesting that you would bring this up. I just missed out on buying a Yamaha DVD-S2700 that I've been wanting to try out. It has OP275 op-amps in the analog section if I'm not mistaken, and I've read good things about that op-amp but have never tried one.

Is there such thing as a dip-8 to soic-9 adapter? I've tried to find one with no luck. I wanted to try out a LME49720 in the headphone section of the CX-1 (to replace the NJM2068SD [soic-9]) that I gave to my son and bought a Brown Dog dip-8/soic-8 adapter but no, that doesn't work.

Cheers,
James
 
Interesting that you would bring this up. I just missed out on buying a Yamaha DVD-S2700 that I've been wanting to try out. It has OP275 op-amps in the analog section if I'm not mistaken, and I've read good things about that op-amp but have never tried one.

Is there such thing as a dip-8 to soic-9 adapter? I've tried to find one with no luck. I wanted to try out a LME49720 in the headphone section of the CX-1 (to replace the NJM2068SD [soic-9]) that I gave to my son and bought a Brown Dog dip-8/soic-8 adapter but no, that doesn't work.

Cheers,
James
The only one I know of that you can manually jump to any pin config, is to use something like this... (pin 1&9 on the SIP is the same V+, so you only need 8 pins)

http://anchor-electronics.com/product/capital-advanced-technologies-9082-surfboard/

Good luck making it the way you want it to be James!
 
Last edited:
The only one I know of that you can manually jump to any pin config, is to use something like this... (pin 1&9 on the SIP is the same V+, so you only need 8 pins)

http://anchor-electronics.com/product/capital-advanced-technologies-9082-surfboard/

Good luck making it the way you want it to be James!

Thank you!

Now I have to admit to having a defctive brain day yesterday. Because after looking again I saw that the headphone amp uses a NJM4556S-A and not a 2068. And looking at my archieved photos I see that I tried using the sip-8 adapter in pins 1-8 where it definetely won't work. But after looking over the data sheets using pins 2-9 it should work. I'll have to try again.

Cheers,
James
 
Thank you!

Now I have to admit to having a defctive brain day yesterday. Because after looking again I saw that the headphone amp uses a NJM4556S-A and not a 2068. And looking at my archieved photos I see that I tried using the sip-8 adapter in pins 1-8 where it definetely won't work. But after looking over the data sheets using pins 2-9 it should work. I'll have to try again.

Cheers,
James
Sometimes just talking it out helps to stir options. ;) Keep us posted!
 
Yes, discussion is always good. I'll try it again and see what happens. My only other concern is that the 4556 has 70mA of output and the 49720 only 26mA. So I hope that the LME49720 has enough ompfh do drive headphones all by itself. There doesn't appear to be any kind of further buffering or amplification after the op-amp.

Another option in the same family that I looked at is the LME49721. It doesn't have quite the same specs as the 49720 (but still quite good) but has an output rating of 100mA. But it shows an absolute max supply volt rating of 6v and it looks like there is about 16v on the supply rails, so I'm guessing that I can't use it.

Cheers,
James
 
Yes, discussion is always good. I'll try it again and see what happens. My only other concern is that the 4556 has 70mA of output and the 49720 only 26mA. So I hope that the LME49720 has enough ompfh do drive headphones all by itself. There doesn't appear to be any kind of further buffering or amplification after the op-amp.

Another option in the same family that I looked at is the LME49721. It doesn't have quite the same specs as the 49720 (but still quite good) but has an output rating of 100mA. But it shows an absolute max supply volt rating of 6v and it looks like there is about 16v on the supply rails, so I'm guessing that I can't use it.

Cheers,
James
Let me make a suggestion, and that would be the OPA-1602. You'll derive the current you're looking for, can swing up to 40V, excellent THD+N, -130dB of channel separation, and is one of the best for phase stability over the entire audio spectrum as you will find. It sounds really good... Lots of commercial DAC's are now upgrading their headphone outputs to the OPA-1602. TEAC uses them exclusively now.

http://www.ti.com/lit/ds/symlink/opa1604.pdf
http://audio.teac.com/news/display/951
 
Last edited:
Let me make a suggestion, and that would be the OPA-1602. You'll derive the current you're looking for, can swing up to 40V, excellent THD+N, -130dB of channel separation, and is one of the best for phase stability over the entire audio spectrum as you will find. It sounds really good... Lots of commercial DAC's are now upgrading their headphone outputs to the OPA-1602. TEAC uses them exclusively now.

http://www.ti.com/lit/ds/symlink/opa1604.pdf
http://audio.teac.com/news/display/951

OK. :) That looks interesting. I'll add a couple to my next Mouser order. I do have a couple of OPA1612 that I bought based on another member's recommendation (I'm being stubbornly dumb and can't recall who at the moment. ?Beau Geste?). I haven't used them yet but based on your sig it looks like you have. Thoughts?

Cheers,
James
 
OK. :) That looks interesting. I'll add a couple to my next Mouser order. I do have a couple of OPA1612 that I bought based on another member's recommendation (I'm being stubbornly dumb and can't recall who at the moment. ?Beau Geste?). I haven't used them yet but based on your sig it looks like you have. Thoughts?

Cheers,
James
The OPA-1612 is the very finest bi-polar op-amp I've used, and in the buffer stage, not much can touch it. It does take a little more supply current to run, and it's output current runs about 2/3rds of the OPA-1602. However, TI does have technical data for using the OPA-1612 for headphones, (which means they do recommend them for that usage) but just be aware of the output. If you find that the OPA-1612 doesn't give you the volume you may want depending on what you use for headphones, the OPA-1602 is your go to chip. But if I had no OPA-1602 on hand but I did have a OPA-1612, man, you bet I'd place it in there. There is light years of performance difference from the 4558. The only place I'd use a 4558, is for a motor controller or a meter driver.

Just an aside, there are newer phones on the market that use the OPA-1612 for high performance DAC outputs for headphones, so if the headphones your son is using sounds okay attached to a mobile device, you can pretty much bet you'll love in in your usage.
 
Last edited:
The OPA-1612 is the very finest bi-polar op-amp I've used, and in the buffer stage, not much can touch it. It does take a little more supply current to run, and it's output current runs about 2/3rds of the OPA-1602. However, TI does have technical data for using the OPA-1612 for headphones, (which means they do recommend them for that usage) but just be aware of the output. If you find that the OPA-1612 doesn't give you the volume you may want depending on what you use for headphones, the OPA-1602 is your go to chip. But if I had no OPA-1602 on hand but I did have a OPA-1612, man, you bet I'd place it in there. There is light years of performance difference from the 4558. The only place I'd use a 4558, is for a motor controller or a meter driver.

Just an aside, there are newer phones on the market that use the OPA-1612 for high performance DAC outputs for headphones, so if the headphones your son is using sounds okay attached to a mobile device, you can pretty much bet you'll love in in your usage.

Thank you! What are your thoughts on the OPA2107? I have some of them also. I use one 2107 and 2x LME49720 in my sound card and like the results a lot.

Cheers,
James
 
Thank you! What are your thoughts on the OPA2107? I have some of them also. I use one 2107 and 2x LME49720 in my sound card and like the results a lot.

Cheers,
James
OPA-2107 are DiFET. They aren't really intended for current audio usage. Instrumentation would be it's primary target. JFET is what many Engineer's opt for, and for that the OPA-1642 is a good choice. The 2107 does have fast settle time though, which is what you need for DAC buffer performance.
 
OPA-2107 are DiFET. They aren't really intended for current audio usage. Instrumentation would be it's primary target. JFET is what many Engineer's opt for, and for that the OPA-1642 is a good choice. The 2107 does have fast settle time though, which is what you need for DAC buffer performance.

You are starting to convince me that I should try a OPA1612 in my sound card instead of the 2107. It's a Asus Xonar Essence STX. I really don't know anything about it internally other than the op-amps in it were socketed from the start. I used the 2107 and 2x 49720 based on someone(?)'s recommendation and like the sound a lot better than before. Looks as I might need to order some more of those 1612's.

Thanks for the discussion, it's been useful and informative.

Cheers,
James
 
Back
Top Bottom