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| Romy the Cat's
personal site dedicated to advanced audio and evolved music reproduction
techniques
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... it may well work superbly. Where it may not be ideal - well, let me explain. The Miller capacitance is not constant but will have some dependence on level (this effect is much more pronounced in silicon). If we feed the valve from a small capacit...
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The feed from feedback goes directly to the grid of the second stage. So the left side of feedback resistor and 110pf cap are connected together. Here is the better drawing of of my final version wit elimination of the cathod cap in the second stages...
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Very good! It is very interesting how you will find the 834PT. Even in stock version (but with OK tubes) I found it demonstrate some interesting qualities. Do not use the 834PT output attenuator of you have one on the unit and make sure that the ...
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The "funny" thing is, the part that "sounds the best" in one situation might not do as well in another situation. A great example I can remember is the fabled Vishay S102 resistor at the grid. Great for stepped attenuators; not good at all at the gri...
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Romy, I also just integrated a new DAC and transport. I tried an Acoustic Revive OCC single signal wire co-ax, and it is OK, providing about what I would expect in the way of "harmonics" from digital, but very good pitch, etc. ...
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[quote user="ArmAlex"]Dear Romy, after a lot of delays I finally found someone technical to build Melquiades. I'm afraid that I may disturb you a lot with questions.Anyhow the first question is:for some of resistors no value for wattage is mentioned ...
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Hi Romy,i want to use the 6E6P-DR (triode mode) as driver in my tube 45 amp.I use a D3A (triode mode) with Anode choke at 180V, 12mA. Grid 2 is connected via 50 Ohm resistor to anode. Grid 3 (pin 8) is connected to cathode.The 6E6P-DR (also 6E6P-E) a...
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Yep, it looks, like very close to “it” design-wise. http://www.studiomaudio.info/loftinwhite.htmlIn the way this amp is one of the manifestations of Loftin-White DC-coupled but it has some own things. The driver stage is the Melquiades Tube to k...
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Romy,Could you help me understand your biasing scheme with this version? I thought I understood the original Milq circuit - but the only channel that looks like that to me is the D channel. I don't get A and B at all! what is the 50 ohm resistor doin...
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Maybe if you didn't try to pull the caps down so fast. Why the hurry? Maybe a 500 ohm or 5k ohm resistor would be a more kind bleeder. I think the peak current spike is not such a good thing for the capacitor. You are also at ...
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I'm giving myself high fives today for nearly solving the broken piano sound in the room. :-)I'm not sure what fixed it, but I believe it to be a shelf half filled with records + two sofas and a carpet.There is room for improvement but it is a g...
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It sounds as though C10 is OK and correctly connected. C2 is OK as well considering it is in parallel with a 30k resistor. The next thing I think, is to turn on the amplifier with both tubes in place and check the current through R21. If R21 and henc...
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Yes, I guess I would sing the different songs if I need to load them differently. In fact Mi might need but I juts refuse to acknowledge it. Nevertheless I am not planning to compromise my phonostage by different loading. BTW, did you try to load the...
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[quote user="Romy the Cat"]I think it is about right. The 6C33C for upper base has 100K
biasing resistor and 20K to ground in Lpad. That would make ~60Hz. This high
pass that unload the LF from the horns that it can’t handle is very important
as y...
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It look like the project progress well. I have a little concern
about heat the will be building up in your PS enclosure. I do not know what
kind ventilation hole you have in there but be advised that it will be quite
hot. In worst case you mig...
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I am sure I made a reply last night, but it is nowhere, so here it is again.44V across R22 is equivalent to 0.88A which is way too high and would require a resistor rated better than 40W. R2 is dropping more voltage than it should. I would look at ...
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Hi Domidaw, it looks like your amplifier is working pretty much correctly. The plate current in the output tube is a little below the recommended range (180 mA versus 200-280 mA in Romy's diagram) but too low is better than too high and you can adjus...
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[quote user="jessie.dazzle"]A possibly dumb question here: When you and Paul give figures in milliamperes, where are you measuring the current (at what points), or are you extrapolating the figure? [/quote] The 6C33C current is measured in mA. The wa...
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[quote user="Romy the Cat"]The wire, the coupling caps, the cathode resistors and many other things are superbly important but it is after the strategic topology is settled. In my view caps, resistor, wire and other things are responsible for the sou...
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Post #2:
R23
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by
ml8
on
2007-03-23
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Romy,That's true that this resistor have negative impact on sound quality. You can run your 6E5P without it as long as you do not get parazitic oscillation.Just connect screen grid and plate electrodes right on tube socket, using shortest possible ca...
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I do not nave, neither I see in the schematic, a resistor
but rather an Lpad shunted with two resistors, exactly how I described above....
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Yes, 5mA is about right. Each 12AX7 eats around 1mA (some time a few fraction of mA more). So, if you have 3 tubes for 1.2-1.2ma each then it will, be around 3.6ma or for all intended purpose you can call it 5mA most likely you ask this question beco...
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[quote user="Romy the Cat"]I mean the driver from 14Hz to 150HZ gas absolutely linear impedance as it has no active load. I look at all of it and felt so tiered and I walked out if it. I think in the new room the horn is shooting into the wide open s...
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Hello Romy,Just thought I'd post my latest re-visit to this cartridge.I've played with this overthe last 2 years on and off between Helikon/VDH MC10. It was ok but did not make a big deal,so I carried on with the Lyra which was finebut not what ...
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R1 (green/brown/orange or yellow/violet/orange) needs to be paralleled with a 12k resistor to bring the loading seen by the cart to just under 100 ohms.
Brian....
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I have coved this subject in past. I was not able to find a solution how to add resistors to change loading and how to make it to be switched that would not degrade sound. So, my own phonocorrector has no adjustable loading. If I need to do it I woul...
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My first guess would be that the hiss you are getting is "tube rush" form upstream rather than an artifact of any resistor/voltage divider. This may mean you still have too much system gain. Again, properly tubed ML2s make NO so...
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that blue motorized ALPS volume pot is utterly waste. the weakest link of the chain of every audio device I've heard. it's a carbon type potentiometer and has a bad effect on the sound unless the pot is used to control a secondary relay ladder resist...
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If you read the post:
http://www.goodsoundclub.com/TreeItem.aspx?postID=41#41
then you know that I am happily employ an interesting 65dB-gain, 7788-7721 two stages phonocorrector designed and build with air capacitors. A few days ago when I eventu...
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I like having a center-tapped filament winding for flexibility. First, you can use a traditional approach on hum balance (what you have now) or use a slightly different approach. I use the center-tap as a fixed DC balance (cathode bias resistor solo...
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