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  1. PatR

    Upgrading Valencia 846A crossovers

    I just picked up my second set of Valencia's. The first set, I built new crossovers for with all new components following the same specs as stock. I added protection for the HF driver in the form of shelving. The original HF Drivers were upgraded with new drivers from GPA. The horn was damped...
  2. PatR

    McIntosh Mc240

    Sure it's an old thread.. but still relevant. I've been through the list of power amps.. I had a completely restored and McShane modded Citation II. This is one killer amp! It sounds great, almost too great. That's the problem. It was so analytical it almost lost that tube warmth. Another down...
  3. PatR

    Increase of 299C power

    If I can, I'd like to jump in on this thread.. I just finished an early LK-72 also. Mine has a hum also, that changes with the volume control it is also in both channels. All can's replaced including a 100/100/100/100@100v from Hayseed Hamfest. For the first section I put a 22mfd (before the...
  4. PatR

    Increase of 299C power

    In regards to voltage readings on the Scott doesn't the schematic call for a 20k ohm per volt VOM, no signal 117 Line. Also look at the % of difference Scott allows for.. 15% on a 430V spec voltages could be off by 63-64 or so volts higher wow. Anyway, wouldn't using a DMM change the readings a...
  5. PatR

    Sovtek 7591XYZ/ EH 7591

    I can say first hand that the TS tubes work fine, they biased right up in the same ranges as a used GE set I have and they sound amazing in this amp. To be fair I have not run it with the GE's I have yet. The Preamp tubes are a mixed bag of american made used tubes. Nothing special. I did plug...
  6. PatR

    Sovtek 7591XYZ/ EH 7591

    ab2forever, thank you for your informative reply. I did read Dave's comparisons. I don't recall the EH tubes being there however. I could have missed them. But basically what you did in your reply is answered the question in simple easy to digest language for anyone to understand. Thanks again...
  7. PatR

    Sovtek 7591XYZ/ EH 7591

    Yet, the TungSol 7591 works fine and the EH is one of the ones that goes off the scale on my Hickok 239.
  8. PatR

    Sovtek 7591XYZ/ EH 7591

    So what's the real deal here. I read a few shootouts online where some comparisons were made. But I'm still confused. I've been playing around with a few Scott amps this past month to explore the wonders of the 7591 tube. The first amp I restored was a 299c/233 it had a quad of 7591's in it and...
  9. PatR

    Scott LK-72 Schematic Needed - pls read

    Well thanks to the wonderful archive I think I found the schematic for mine. Early version with no pots.
  10. PatR

    Scott LK-72 Schematic Needed - pls read

    This is an old thread for sure, but I'm in the same fix as the original poster. I think I have the same LK-72 that I am rebuilding now. It is not an A or a B as posted on the Scott website, but it does seem to have a little of both. There are no balance or bias pots or test points and mine has...
  11. PatR

    Mr. Carlson's Lab Repairs a Hartman Kardon Citation 1 Pre-Amp

    Nice to see him tackle a classic like the Citation I. I love my Citation I
  12. PatR

    HH Scott Restoration and Cabinets/Installing unit.

    Howard, what's odd about mine is there are nylon "sockets" in the bottom cover that would accept a screws. But only two near the rear. Nothing up front..
  13. PatR

    HH Scott Restoration and Cabinets/Installing unit.

    Yes Dave, this was one of a host of modifications that honestly made no sense to a guy like me. I'd rather bring it back to spec the right way as opposed to modifying it to work with the wrong tubes (Sovtek Tubes). These Sovtek's were the early version that I can't confirm but someone down the...
  14. PatR

    HH Scott Restoration and Cabinets/Installing unit.

    On this unit I'm still looking for some advice and or pictures of mounting the amp in a sheetmetal "Scott" cabinet. I have two of the woodgrained metal cabinets. My amp only has two nylon threaded inserts near the back of the amp and nothing up front. Does anyone have ideas of what goes on the...
  15. PatR

    HH Scott Restoration and Cabinets/Installing unit.

    Dave, The old transformer is in one of the pics above. It is TR-13-3-4 606524. I haven't tested it out of the unit yet.. in the unit it was showing some voltages that were really alarmingly high on line power and even high on a variac set to 110 volts. But with the higher line voltages today...
  16. PatR

    HH Scott Restoration and Cabinets/Installing unit.

    Hi Dave, after the final transformer install and the last few parts, I checked all voltages against the print with a calibrated Heathkit VTVM and the voltages were all within spec of the ones on the print. Any differences so minor that I did not even give them a thought.. for this reason I did...
  17. PatR

    HH Scott Restoration and Cabinets/Installing unit.

    HAHA, see I did it again.. Always adding that K on..
  18. PatR

    HH Scott Restoration and Cabinets/Installing unit.

    This was a case of.. "I have an HH Scott 299C do you have a transformer for it?".. the answer was "yes we will have to wind one for you, it will take about 3-4 weeks".. I didn't get into any specifics with them, which now after understanding all of the Scott variables involved I should have...
  19. PatR

    VTA Upgrade to Dynaco ST-70 problem.

    Check bypass resistors. I just had a similar problem with a Scott 299C where I mistakenly replaced to 2.7k with 270k resistors. Same symptoms. Loss of gain and distortion in a portion of the frequency band like you describe. I cleaned my bifocals, replaced the resistors with proper value and...
  20. PatR

    HH Scott Restoration and Cabinets/Installing unit.

    Here is a shot of the amp in the early stages of restoration, before I dug in and really replaced parts. Also a shot of the bridge rectifier. It's a larger one, but I like the lug type and I was able to pop rivet it to the chassis. It works fine so no worries. New transformer installed and...
  21. PatR

    HH Scott Restoration and Cabinets/Installing unit.

    Here are some pictures.. this is when it arrived and after about an hour of cleaning. It cleaned up well.. little tip I found for those that want to try it. Deoxit cleans this type of amp face well without any apparent damage. I've used it on dirty mac face, this face and a Citation II face all...
  22. PatR

    HH Scott Restoration and Cabinets/Installing unit.

    Hi all, I just finished up a long and grueling restoration of a 299C/233 schematic. I replaced everything, new Heyboer power transformer (the original gave up the ghost). The unit came with Sovtek 7591's and the PO had changed the 270k Bias resistors down to 15k for who knows what reason? With...
  23. PatR

    Scott LK-72 Rehab

    Thanks Mibag6 and Dave!! Once again the legendary Scott schematics at play. Once I dig into this thing, maybe I'll take some pics and start a rebuild thread.
  24. PatR

    Scott LK-72 Rehab

    Hope I'm not hijacking, but since this is a Scott LK-72 thread I thought it would be okay to just ask here as opposed to starting a whole new thread for a simple question. I have an LK-72a that I am about to start rebuilding. Lots of good tips here in this thread for sure.. My question. After...
  25. PatR

    What speakers do you listen to with your tube amp?

    Like the OP I have a VTA-70 that I built from a kit. It's being fed by an HK Citation I that I rebuilt and I use a pair of Altec 604c's in original Altec 606 Corner cabinets. That have GPA crossovers that have been modified to work better with the 604c and I added a shelving resistor to the HF...
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