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tube fanatic

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  1. I would check the frequency of the AC coming out of the generator. If the generator is a non-inverter type, it's possible that the frequency is lower than the required 60 Hz. The lower the frequency, the less voltage headroom the amp's power transformer can provide (in addition to raising its operating temperature). So, if you're only getting say 55 Hz AC from the generator, you may not be getting enough voltage to allow the amp to deliver its full output. Pushing the amp into clipping is likely to engage the protective circuitry to prevent damage to the output transistors.

  2. One of my local audio guys found a bunch of 7695s at a hamfest and talked me into prototyping a single ended/dual mono/separate power supply amp around them (he paid for all of the parts, so I couldn't refuse). It's 50s style construction (he didn't want to spend the extra $$$ for a chassis with a fancy wooden base, etc.) and sounds really amazing with his CWs. The power supply provides very highly filtered DC for the filaments as well as the B+. Hum is vanishingly low, bass output is huge, and it has the midrange and top end of a triode! I came close to paying him for the parts and keeping it, but then he would have stopped talking to me!!!



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  3. Thanks for the additional suggestions. What type of price range would I be in for some of the above listed amps...roughly?

    Again, it depends on where you purchase it. As an example, many of the lower power Scott amps (like the 299 series) can be found for $300-500 depending on the condition. I used to have a flat restoration fee of $500 for such amps (not including tube replacement- that was additional); but, that included services which many restorers do not provide (no point in going into detail as I no longer do this for the public). Let it suffice that it went way beyond just replacing some capacitors, setting the bias, and calling it "restored." So, look around and carefully check the credentials of the person you choose to do the restoration before committing to do so. There are folks out there who have a multimeter and soldering iron and call themselves professional amp restorers!


  4. So, how much should I be budgeting for a good tube amp to power both speakers? I know Mc amps are about twice my budget. Is that what I need to be considering?

    A good tube amp is going to run you at least $500-1000, unless you
    build one yourself from parts scrounged from equipment that's been
    thrown away. One of the better values out there is the Jolida 102b which sells for around $650 (it features the all important balance control which is often lacking in many currently manufactured tube amps). It has the advantage of being new, with a warranty. Many dealers also sell them with a return privilege in case you are not satisfied. Most vintage tube amps will need to be electronically restored; doing that properly can be expensive; and, of course, once you buy it it's yours whether you like it or not.

    Why do you say that if you buy its yours whether you like it or not..... People sell and recoup most of there bucks spent on vintage all the time. The key is to buy one in nice cosmetic condition and have someone reputable rebuild it. They hold value way better then some cheap chinese made Jolida....and sound a heck of allot better to boot!!

    Well, firstly, vintage amps do not necessarily sound "better" than currently made Chinese units (in fact, some sound like garbage no matter what you do to them). Try some blind listening tests between restored vintage stuff and some of the current Chinese units and you will be amazed at the preferences of the listening audience. Secondly, your comment about having someone reputable rebuilding it is the critical factor. Many people buy vintage equipment from, or have vintage equipment restored by ostensibly reputable technicians who turn out not to be what they represent themselves to be. I've dealt with that issue for decades; and having to undo what someone else did is far more of a pain than rebuilding a factory job. So, as far as recouping one's investment in a vintage unit, much depends on what's "under the hood," and not just surface cosmetics.

  5. How about a nice used vintage integrated, like HH Scott, Eico, Fisher, etc.? They all sound wonderful with Klipsch Heritage speakers.

    Mike


    I'd be all for it so long as the maintenance isn't killer. If I do go vintage with tubes, what kind of upkeep might I expect?

    If the amp is fully restored, the only maintenance likely to be needed is tube replacement. Depending on how the tubes are set up (i.e. whether they are being run conservatively, or being pushed to their limits, whether they are properly ventilated, etc.), life span can be short or considerable. Given that most of the tubes used in vintage amps are available from current manufacturers (as opposed to new old stock US, Canadian, or British tubes), the cost of replacement won't necessarily be huge. But, as I mentioned in a previoius post to your question, you must factor in the cost of a full restoration in the purchase price of the amp. Don't be pulled in by someone who says that they replaced the "essential" parts, but left everything else. There are many areas in which vintage amps can fail, and unless all of these are addressed, you can be in store for a costly failure down the road.


  6. So, how much should I be budgeting for a good tube amp to power both speakers? I know Mc amps are about twice my budget. Is that what I need to be considering?

    A good tube amp is going to run you at least $500-1000, unless you
    build one yourself from parts scrounged from equipment that's been
    thrown away. One of the better values out there is the Jolida 102b which sells for around $650 (it features the all important balance control which is often lacking in many currently manufactured tube amps). It has the advantage of being new, with a warranty. Many dealers also sell them with a return privilege in case you are not satisfied. Most vintage tube amps will need to be electronically restored; doing that properly can be expensive; and, of course, once you buy it it's yours whether you like it or not.
  7. I used K-horns on a carpet covered concrete slab for many years and they were phenomenal! With any speakers, I've always found that there can be some bass enhancement when used on a wood floor vs. concrete probably due to some resonance effects. But, with K-horns that certainly shouldn't be a factor! Try it and I'm sure that you won't be disappointed.

  8. Yes, the good old days. I remember when working overseas we would order Fisher stuff by the pallet with export packing 50% off list.

    JJK

    The good old days indeed! My buddy, when he was in the Navy and stationed in Greenland, bought all kinds of incredible stuff (like Tandberg tape equipment) at prices that could make my hair fall out if I still had any!!!

  9. I know it's subjective, but could someone describe the particular sound of a Luxman that makes it special?

    Luxman equipment does not necessarily sound better than anything else out there. In fact, some of their older SS equipment sounded positively brittle and awful! As mentioned before, you need to hear the equipment in your own system and draw your own conclusions. If you find the sound pleasing, then it's good!

  10. Does anyone know about this tube receiver? I've read some very positive reviews. Owner claims it works perfectly-- no hum or any other problems. But it still has original tubes. I didn't know tubes last that long or perhaps it wasn't being used? Any comments would be appreciated.

    In restoring a receiver like this be certain that the tech also does a restoration of the tuner section, including but not limited to a total realignment. Many restorers only deal with the power supply and amplifier sections while totally ignoring the rest (not a big deal if you are only going to use the amp and not listen to radio; but if you're spending money, why not do everything?). But, keep in mind that if you do a total restoration, it can be quite costly. In the shop we did the total restoration 99% of the time to ensure the greatest value for folks who collect vintage receivers and want them completely functional, and up to specs, in all aspects.

  11. A 5Z3P.

    It looks like that tube only uses four pins. Does it have the key on the center post or is it possible to put it in the socket incorrectly?

    Bruce

    The US made 5Z3 has a 4 pin base with 2 pins having a larger diameter than the others to prevent improper insertion. The 5Z3P seems to have an octal base.

  12. Removing the rectifier tube immediately after shutting off the amp should not cause any problems at all. So, I'd say that since the tube is not lighting up, something happened to its filament which is coincidental (unless there's a bad connection to the tube socket which is causing the difficulty). I don't have any experience with the Chinese tubes, so I can't comment on their reliability; however, the US made 5Z3s were extremely robust tubes which could take an awful lot of punishment without failing. Since the Chinese version has an 8 pin octal base you, unfortunately, need to stay with the modern replacements. Putting in a new one should should fix your problem.

  13. Today I removed the rectifier tube from my 300b amp immediately after I had just turned it off. I did this absent mindedly, fearing that doing such a thing could cause a problem. The problem is that the amp will not work now. I am assuming that removing the rectifier tube after just turning it off, or was it still on, could have blown the tube? Has anyone ever done what I did, and what was your outcome? Thanks in advance.

    When you say that the amp doesn't work, what do you mean? Is it totally dead? If the amp has a pilot light (i.e. power on indicator), does it work when you turn it on? When you turn it on, does the rectifier filament still glow, and does the 300B and tubes other tubes still glow?

  14. "The time came to make the 500 mile round trip to pick up the 6100. As my
    tech friend and I were talking, I noticed he was running a Citation 12
    amp just like mine. He told me a horror story about how it went into
    complete fail, dumping enough DC into his speakers to fry the voice
    coils. I hate those kind of stories."

    Makes a good case to go with tubes- with many designs there's no concern about any DC getting into the speakers!

  15. The CA-5/PA-5 combination was fairly well regarded although some people felt that the sound was a bit brittle and "solid state" sounding (typical of many designs from that era). K-horns are one of the most revealing speakers around and will make you very aware of any deficiencies in the equipment used with them. So, the only way to know if the sound is what you're looking for is to try it yourself and draw your own conclusions. Cambridge Audio and Marantz both offer CD players in the $500 price range. Their products have received many favorable reviews and comments. Buy one from a dealer which offers a return privilege just in case you are not satisfied. For speaker cables up to 15-20 feet in length I prefer old fashioned #16 lamp cord which you can get at your local Home Depot among other places. Interconnect cables can be anything decent and inexpensive. You will be given many different opinions on these last 2 points! Ultimately, you will need to do your own experimentation based on how much you want to spend.

  16. My uncle had a Heathkit system with a Garard changer set to 6 grams with a GE VR1I which tracked perfectly with ZERO distortion accross the whole record. Never seen anything or heard anything that would even come close to it's performance and I have heard a lot of records and turntables. There were no pops, crackles, or rumble. Not even one pop and if you played a record that you know had pops it would not pop on his system.

    JJK

    With a 6 gram tracking force I'm surprised that you didn't see vinyl shreds coming off when the record was played!!!

  17. The tonearms used in most of those old turntables as found in the 50s and 60s consoles track with excessive force (we used to refer to their tracking force in "pounds" back then, although it wasn't quite that bad!). In addition, the styluses weren't exactly benign in their treatment of records either. So, in considering going to vinyl, you may want to install a modern turntable (with a built-in preamp) in the interest of preserving the records that you play.

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