Dflip Posted July 19, 2003 Share Posted July 19, 2003 I have a Rega Planar 3 with a 125RB arm and a Grado Platinum cartridge. The Platinum model uses a modified four piece OTL cantilever technology achieving a 10% tip mass reduction over the Prestige series and ultra-high purity long crystal (UHPLC) oxygen free copper wire in the coils. A assume this means it is a moving coil cartridge. The problem with using the Scott LK-72 (35 watts), the efficiency (4.5 mV) of the cartridge leads to a very quiet volume (well, maybe 9:30 on the volume dial when it is actually turned up all the way). The sound quality is also flat, no real dynamic range, just a lot of mids. The line stage sounds great, GE 5751 blackplates. The phono section, Telefunken 12AX7's is not up to snuff. I have talked to Craig and there is no internal fix available, so I need to look for an external solution. It is a gain difficiency problem. On the net, I saw a Creek moving coil phono stage, OBH-9 that could be interesting, also a Trichord Dino. Here are the websites, Creek: www.creekaudio.com/products/obh/obh_8_9.asp Trichord: www.phono-stage-riaa-step-up.com/ trichord-phono-stage.htm Any comments or ideas for this problem? I could go back to a mm cartridge that has more gain, efficiency. I don't use the turntable very often, but every so often would like to put on a song that I don't have on CD. Well recorded CD's sound great, so playing albums where the sound quality is not up to the rest of my system is not worth it. Sort of like playing 60's music that was first put on CD, sounds fine on a $350 mini system, but not with Klipsch and Scott. Don Quote Link to comment Share on other sites More sharing options...
NOSValves Posted July 19, 2003 Share Posted July 19, 2003 Okay now I'm getting confused. Did you or did not tell me that you tried a different cartridge and everything was fine ? If your grado is indeed a 4.5 mV cartridge it should work absolutely fine unless some thing is wrong with it. This could be that the cartridge is installed improperly or just plain defective. Did you try another cartridge or not ?? Craig PS Dean just confirmed that the cartridge is indeed a MM with 4.5 mV so if its working right it should work. Quote Link to comment Share on other sites More sharing options...
Dflip Posted July 19, 2003 Author Share Posted July 19, 2003 Craig: I originally had a Shure V-15 Type IV cartridge in the set-up, before I got the Scott. It worked fine way back when, then I messed up the connections and stripped them. About a year and a half ago, I had the turntable fixed, wires resoldered and bought the Grado. I am playing it now at about 3 pm on the dial and it is a touch above comfortable listening level. The dynamic range is okay, but not spectacular. It seems to lack a bit of bottom end. It sounds better right now, Crusaders and George Benson, but I have not been listening to CD's tonight. I have not tried putting the the Shure back in, I would have to remount the head and line it up properly. The Grado was aligned up a stylus guide and set to track properly by somebody who seemed to know what he was doing. He set me onto looking for a tube amp to match my Klipsch in the first place. He has been the business for 20 years and fixed my Acurus gear when I blew a transformer. Just trying to get my head around the sound and why it is different. Maybe I am trying to be too analytical and wanting perfection out of what I have? Don Quote Link to comment Share on other sites More sharing options...
NOSValves Posted July 19, 2003 Share Posted July 19, 2003 What inputs are you using ?? High or Low ? Quote Link to comment Share on other sites More sharing options...
Deang Posted July 19, 2003 Share Posted July 19, 2003 Don, that is definitely a moving magnet and should work fine. You may have an issue with the alignment. Even people with experience can make a mistake. The Scott is fine -- start taking a hard look at the cartridge set up. Quote Link to comment Share on other sites More sharing options...
Dflip Posted July 19, 2003 Author Share Posted July 19, 2003 Craig: The amp does not give me a choice between high and low imputs. RIAA phono has only set of plugs. There are a set of female RCA's for NAB (tape), Tuner, Extra (CD), Center Channel Output (tape recorder) and Playback. I have a manual from somewhere that mentions the option, but the second set of plugs is not there. Dean: Thanks for the assistance. I will have to go see the installer next week. I will try it out on his system, he has a set of ASL 50 watt monoblocks and a Rega Planet hooked up to a pair of Totem Signature Model 1's that sound very nice, great imagery and detail. I can't on early in the week, my friend is having day surgery, and then will need two or three days of tender loving care. Her mom is undergoing cancer treatments so she really does need my help and support. Later in the week I will check it out. Don Quote Link to comment Share on other sites More sharing options...
NOSValves Posted July 19, 2003 Share Posted July 19, 2003 I think we have now found part of the problem. The variation of Scott amps never ends. I swore they all had High and Low inputs. I know 299C do. I will ask one more time have you ever tried a different cartridge/table ?? I swear you told me you did and all was well. Craig Quote Link to comment Share on other sites More sharing options...
NOSValves Posted July 19, 2003 Share Posted July 19, 2003 Okay I have a way we can adjust for the input of your cartridge but before we do this I want to know for sure that there is a problem with the amp. You need to either try your cartridge/table on another amp or another cartridge/table your amp to confirm its not your table that is the problem. Craig Quote Link to comment Share on other sites More sharing options...
Dflip Posted July 19, 2003 Author Share Posted July 19, 2003 I think at some point I finally gave up and may have said it was fine. Probably after a long day of marking or something, eight hours of reading a wide variety of grade eight work does that to me. I'm sure that I confused you, it wouldn't be the first time. Thanks for your patience. It doesn't sound awful, but as with most of us, l am looking to improve it a bit. The manual seems to indicate that it should have high and low inputs, but it doesn't. As you said, part of the never ending variations in Scott ampsl Quote Link to comment Share on other sites More sharing options...
NOSValves Posted July 19, 2003 Share Posted July 19, 2003 do you have any other amp witha phono stage you can hook this table up too ? The fix will be very simple but hard to get to . If the problem is with this High level input and not your table there will be one resistor that we will need to either get rid of or change the value that is connected right to the center pin of the female phono RCA's. I bet its either 100K or 150K and needs to be 47K or nothing at all. Craig Quote Link to comment Share on other sites More sharing options...
NOSValves Posted July 19, 2003 Share Posted July 19, 2003 What you need to do is open the amp up and look at the back side of the RCA jack and confirm if there is a resistor hooked to the center of the RCA jack. Also tell me what the color banding is first 3 colors is all I need . I bet its 100K brown/black/yellow if so what you need to do is remove both resistors (one on each jack) and solder a solid wire in its place you will then have a low level input. Craig Quote Link to comment Share on other sites More sharing options...
Dflip Posted July 19, 2003 Author Share Posted July 19, 2003 I have a SAE preamp with a phono stage that I used to use with my Acurus amp and preamp. I used it because the Acurus RL-11 does not have a phono stage. It can be hooked up. Do I run the turntable to the SAE and then the SAE into one of the inputs, eg. Extra where my CD player is or the Tape recorder input? Quote Link to comment Share on other sites More sharing options...
Dflip Posted July 19, 2003 Author Share Posted July 19, 2003 What you need to do is open the amp up and look at the back side of the RCA jack and confirm if there is a resistor hooked to the center of the RCA jack. Also tell me what the color banding is first 3 colors is all I need . I bet its 100K brown/black/yellow if so what you need to do is remove both resistors (one on each jack) and solder a solid wire in its place you will then have a low level input. --------------------- I will try this in the morning. I am tired and it is time for me to call it a night, almost 1 am. Thanks for the help. I will unplug the amp and try not to electricute myself. Don Quote Link to comment Share on other sites More sharing options...
NOSValves Posted July 20, 2003 Share Posted July 20, 2003 Yes please do unplug the amp !! Do that now and everything will be discharged by morning so no danger of getting shocked. To get to these restistors you will have to take the 2 screws on each side of the apron and the 3 on the top out and gently tilt the apron open to work on the RCA jacks. Craig Quote Link to comment Share on other sites More sharing options...
bkrop Posted July 20, 2003 Share Posted July 20, 2003 Try cleaning 40 years of oxidation off the RCA connections! Quote Link to comment Share on other sites More sharing options...
Dflip Posted July 20, 2003 Author Share Posted July 20, 2003 Craig: I tried the SAE preamp this morning and wired the phono outputs into the SAE and the outputs from the preamp into the EXTRA RCA inputs on the Scott. The sound is good, I have volume and detail. I guess this means the turntable and Grado are fine. (Edited section) (I went back and also connected them to the Playback RCA's at the back and then used the Tape Monitor switch). This also seemed to work. I will turn off the Scott and let it discharge for the afternoon. I have my friend's daughters birthday get together to attend. When I get back I will open up the LK-72 and see which resistor is attached to the RCA jacks. It actually sounds pretty good. Now I am starting to understand why people like listening to vinyl, a different sound than CD's, but also very good. Just have to deal with the pops. Don Quote Link to comment Share on other sites More sharing options...
Allan Songer Posted July 20, 2003 Share Posted July 20, 2003 Pops? What are pops? Haven't heard them in years . . . . Keep listening---they'll fade into the background before you know it. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted July 20, 2003 Share Posted July 20, 2003 If you have quality vinyl the pops are just not there ! It just takes some serious looking to find good copies that have been either not used or very well cared for. Craig Quote Link to comment Share on other sites More sharing options...
Dflip Posted July 20, 2003 Author Share Posted July 20, 2003 I have been talking to Craig privately today about the problem. As some of you might know the Scott LK-72 is a kit amp. Whoever put it together put a 100K resistor at the end of the RIAA phono jacks, therefore I got about 30-40% of the volume I should have got. Craig's suggestion to check for a brown, black, yellow resistor yielded the offending item. I removed it and resoldered in a piece of 18 awg solid wire and the problem disappeared. No resistor and the sound comes through the way it should. I am listening to The Best of the Crusaders right now and enjoying it. Now I have a choice of vinyl, CD's or a vintage Scott LT-110 tuner, a no lose proposition if you ask me. Craig, thanks for the help as per usual. You provide great advice and are prepared to deal with lots of questions from me trying to get it right. Don Quote Link to comment Share on other sites More sharing options...
NOSValves Posted July 20, 2003 Share Posted July 20, 2003 You did a great job ! I just wish we had pursued this a long time ago ! Craig Quote Link to comment Share on other sites More sharing options...
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