Is my RKV Mark II a dud?
Jul 17, 2001 at 5:37 PM Post #17 of 30
Quote:

Originally posted by flashbak
Well when you parallel resistance you actually lower the value of that resistance!


So doesn't that mean that you would want to put it in series (resistors, not transistors)? This is just a guess, as I am not much of a DIY-er, I'm not sure what that would do to the whole LRC circuit...
 
Jul 17, 2001 at 6:18 PM Post #18 of 30
I'm pretty sure that the impedance matching would be done with a transformer, not resistors. This basically just changes the amp from output-transformerless (OTL) to transformer-coupled, which is what speaker tube amps generally are.
 
Jul 17, 2001 at 7:20 PM Post #19 of 30
A transformer would do the job. But you would have to wonder about the possible sonic penalties that you might encounter using one.

Vertigo, I would stick to the 600s.

Is the amp still working with no problems (with the Senns)?
 
Jul 18, 2001 at 11:02 AM Post #22 of 30
It seems the tubes that came with the thing were at least having problems (probably the reason the seller sold the RKV, given how hard the PCL 805 tubes are to find, as I found out), even up till now. Thinking I found the problem, I tried swapping back to the old tubes, as to not waste them if they still worked...but nope, the funky warped sound came back using the Senns. So the old tubes are probably bad period, with no hope for them. And yet, if I turn the amp off and on again, the sound will return back to normal, if for a brief period only.

By warped sound, I mean the sound will gradually start dimming, and the soundstage will slowly narrow into pratically nothing. Not sure if you would call this clipping, but it seems to be a problem with the tubes, rather then the amp itself.
 
Jul 18, 2001 at 12:41 PM Post #23 of 30
Vertigo-1,
That certainly would indicate a failing component. You really should have it looked at by someone who can measure circuit voltages, scope it, and signal trace it! I hope the person who sold it to you gave you a really great deal on it! Did that person indicate that it had some problems during the sale process?
 
Jul 21, 2001 at 1:03 PM Post #24 of 30
Vertigo-1,

I suspect that there is something wrong w/ the unit as I had been using Grado RS1 w/ it for nearly a year w/o a glitch before matching HD600 w/ it for much lowered residual noise level. Therefore it should drive R10 well w/ your new tubes. I'd be glad to help you. I suspect the new tubes you use may also be duds as it happened to me before a couple of times. You may email me in private if you prefer.

Jan's method works in the cost-effective way for SOLID STATE gears! For TUBE gears, either one uses a transformer or bloody caps (hampers dynamics) to enable low impendance output. Otherwise, the cost is much too high to have an OTL w/o caps even though such design is feasible.
 
Jul 21, 2001 at 1:20 PM Post #25 of 30
Actually, this thing is easy to find as quite a few dealers have it except:

1. if dealers carry it, few has a quad left
2. if dealers carry it, few has a quad in the same brand
3. if dealers carry it, few has a quad in the same premium brand

Thus, I have been dreaming about locating the second sets of Telefunken, Siemens and Amperex for a year and still keep on dreaming. After they burn out, I have to settle w/ Ediswan and Philips for maybe the rest of my life.^_^
 
Jul 21, 2001 at 1:34 PM Post #26 of 30
Bootman may be right in that R10 may dip much lower than 40ohms. If you find the "warp" starts quicker from a bass heavy title than no or little bassy title. Then you may have hope to correct it by buying a matching transformer or using larger coupling caps to store more juice for the tube unfriendly Sony. Otherwise, it seems like you have to stuck w/ HD600 like me.
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If you are not afraid of using solder and bearing risk, try to contact Mr. Becker, the designer, at audiovalve@aol.com. The Beckers are very friendly and helpful over the time I have been owning the amp.
 
Jul 23, 2001 at 8:59 PM Post #28 of 30
No, it's not the doomsday scenario. Nevertheless, I missed Grado and have been regretting selling it. Personal preference, once developed, is hard to change even though HD600 is no slouch at all. I don't have chance to listen to R10 but it should be highly addictive as the (dynamic) headphone king!
 
Aug 5, 2001 at 11:51 AM Post #29 of 30
I think the problem all along was actually a bad upper headphone jack...my R10s seem to be working just fine on the second jack, and I've ran through 2 CDs so far. Man I'm glad to finally get the RKV up and running (not to mention I'm glad to be back with the RKV and R10s
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)...

templeboy, definitely give the R10s a try if you can with your own system...it takes a little time to adjust to their sound and their price, but once you settle in with them, the R10s just totally bowl over all the other dynamic headphones out there. They just simply sound like THE reference headphone...and in comparison, everything else just sounds very colored or just strange (not a good way to put it I know, but there it is). I'm completely in love with my R10s now...I believe in a month or so, I could happily relinquish all my other headphones, without ever looking back...even my holier-than-thou Grado HP-1s.
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