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About hirsch
- Birthday 10/19/1953
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The current crew. Rufus (black)runs things. Hugo Z Hackenbush (Maine Coon) is the baby and gets into just about everything. Molly (brown tabby) stays out their way
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A belated thanks for all of the birthday wishes! I haven't been online very much lately due to a surprise change in my circumstances (surprising to me, at any rate). I'm now engaged to be married. 58 years of bachelorhood coming to an an end.
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I've had this amp since July 10th. I'll post a review in a bit. However, the short version is that it's the first amp I've owned that lets me enjoy the K-1000 enough to make it a daily user. More coming soon. [ATTACH=CONFIG]3542[/ATTACH]
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Sad news indeed. I've been a fan for a lot of years. The Fugs Final CD Part 2 came out this year, but I was hoping for a much longer running series. One of the most influential musician/poets that few people ever heard of. RIP.
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I was really hoping to get to this one, but a conflict came up and I've got to go down to NC instead. I will get to another one of these if I have to host a DC Canjam myself. I may curse myself for having written that.
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NKOTB - TTVJ/Millett 307A Headphone Amp
hirsch replied to n_maher's topic in Headphone Amplification
Government polices on personal use of government computers/software are actually pretty lenient up to a point. However, it is absolutely illegal for a federal employee to use a government-owned system for personal profit. It would have nothing to do with any software licenses or contracts at all, but rather the government's policies for use of equipment that it owns. -
I haven't changed tubes in mine for at least six years. I use Telefunken PCC88's, and those tubes last. My amp was modified by Carlo, and is better sounding than the stock version. Even considering the mod cost, you'd have to spend a lot to get an amp that could match the sound, much less better it. Even in its stock form, the SHA-1 at its going rate is a steal compared to some of the crap out there. A rep can develop when someone listens to an amp with crap tubes and then makes conclusions about the amp without even realizing that he's never really heard what it should sound like.
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Mine also. My first impression was that it may have been one of the best K-1000 amps I've heard (and that Pete really needed a better source). I've got some pictures from my cell phone. Will try to upload them at some point when I get a minute and post them here and at the other place.
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The headphone jack on the MicroZOTL was an afterthought. It reportedly came about when Berning was discussing the ZOTL with reviewer Dick Olsher, who suggested the idea. The ZOTL was originally conceived to be a 2WPC speaker amp for office use. It was also designed to show that Berning's zero-hysteresis OTL technology could be implemented in a relatively low cost design. There were no transformers in the amp (not even the power supply, which was a switching type). That accidental headphone jack probably sold more ZOTL's than the original concept. The MicroZOTL was my reference amp for a long time back in the day. As a headphone amp, the bass on the ZOTL was never completely convincing, but the mids and highs were superb. Berning is a talented designer, and if he went about designing a headphone amp for that purpose without cutting corners, I for one would really be interested in hearing the result. A speaker amp modified for headphone use is likelier to be better with low impedance headphones. Remember that speaker amps are designed for loads around 4 to 16 ohms. A "low" impedance headphone is normally around 32 ohms, so would already be at the high end of the impedance range for which the amp was designed. A high impedance headphone (300 to 600 ohms) would not be the type of load for which a speaker amp is built. The designer would be the best judge of how the circuit would be affected by load. Since it doesn't exist yet, nobody can actually have heard it.
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Settings for testing 5998 tubes in a tube tester?
hirsch replied to shellylh's topic in Headphone Amplification
The 747 is a farily reliable tester, and one that I use regularly. However, it's got some issues. First, there are almost certainly some inaccuracies in the setup manual (endemic to all testers). Second, the tester needs to be calibrated. Instructions are in the manual, but it's a pain in the butt to do it. If your tester is stable for long periods of time, it need not be done often. I keep a set of known tubes just to test periodically. As long as I get the same readings at different times, I'm fairly confident that calibration hasn't drifted. If you do get consistent drift over time, then an overhaul of the tester is probably in order. Finally, there were changes in tube production over the years. Some tube types changed radically. I've had NOS tubes test near 100 for some vintages, and the same type from a different brand/year test at 10%. I also use a Heathkit TT-1A, which can often get accurate readings on tubes that the B&K has trouble with. Finally, a low reading on the tester does not necessarily mean that a tube is not NOS. Some tubes simply read lower than others. Many will never get near 100 on the 747's scale. If you believe that a tube is NOS, try doing a life-test. The life-test reduces filament voltage by 10%, but also provides a compensating signal boost. A tube is considered "good" if the actual drop in signal is less than 25%. However, NOS tubes can be insensitive to the small drop in voltage (tubes become more sensitive to this with wear). What you might see then is an actual increase in gm when you do the lift test. If you see this increase in gm, or at least no drop, when you perform the life test, the tube is probably near NOS at least, regardless of the actual gm. You can do this with a larger voltage drop by reducing the filament voltage manually. If you test a 6v tube at 5v, and the results are still fairly consistent (only a minor drop at worst), the tube is likely very strong, again regardless of actual gm. -
Got BDP-83SE back from Oppo yesterday. First impression is based on movie watching only, but FWIW this thing sounds good. Clean precise imaging, very fast and detailed, strong low-end performance. Great value for $300 on top of the original player cost... and that's before the burn-in. (Using 7.1 channel analog output into Outlaw 990. In comparison, digital input to 990...sucks)
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The alternative sucks much more.
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HE90 > HE60 > the rest of them I listened to the HD800 on a bunch of amps, but for some reason it kept sounding like an HD800 which wasn't a sound I particularly liked. There may be a magical amp out there that transforms it (a friend on mine likes it with the Luxman P-1, although I didn't think it was that great a combo). I just never really enjoyed listening to the headphone.
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MicroZOTL, SHA-1, HP-4, Supra and whatever other amps came through. Every amp I ever used to compare HP-1 to HP-2 required significantly more gain on HP-1 to volume-match to HP-2.