Back in the good old days, folks used to call their distributor with questions like this. We'd ask the relevant questions and supply the correct parts. It would often take five to ten minutes.

With this internet thing, we get to have the process drawn out over time, with multiple trips to the job site, clearly enhancing profitability and customer satisfaction.

Ahh, progress.

Fred, truth be told but you and Capitol are a rare and dying breed! What do you think my response would be if I called up AVAD/Snap/ADI/etc asking these questions? Nothing, dead air, silence.....

Again, this isn't really a matter of whether something works or doesn't work. I guess I was hoping to hear a little insight (general overview) of what/why older amps are better and maybe a recommendation as to what direction I should go (ie Marantz, separates, etc). I understand the problem with this BROAD question so I apologize for not keeping laser like focus in the original question.

Something like:
I need suggestions for surround receiver/amp to compete with an older more powerful amp and it has to be better than the Yamaha A730. Something around $1200 or less.

I know one way to keep us from becoming "a dying breed".

drewski,
Back in the old days, when we had successfully dodged the dinosaurs for a few hours, we sat and listened, nay concentrated on listening, to music. The amplifiers were of very high fidelity. And medium. And low. But low still sounded okay because we didn't know better.  The speakers were of much wider variety than amps!

These days, truth be told, the amplifiers themselves are at about 98% of the quality of the best ones from back then. One guy I know says "pick what you want, it's all the same crap." But he's comparing against terribly esoteric systems. It's likely true that Marantz, Yamaha, Denon, Integra, Onkyo, etc. are all the same crap, but still are very good and high fidelity equipment, especially compared to such things as the Sansui units that every serviceman deployed to the Pacific in the sixties and seventies brought home.

When we are trying to install something and it sounds like crap, something is wrong, as plain as that. When it's a technology that's not understood, like phono cartridges and preamps, it's important to realize that you can't make it sound better without understanding. Fred said all of that in the first two lines of Post 31.

Teach your installers, and do this yourself: be ready to be humble and accept that weird problems with products you're not trained on require assistance from people who understand them. Come here to remotecentral. Email me -- I started buying 1940s equipment in the 1960s and I've run across some pretty strange stuff, stuff that I can help you with. Like you know the CAT5 color code, I used to know the cartridge wiring color code. I've forgotten it, it's been so long. But I and others here understand the equipment.  Some day you'll run across a radio where the magnet of the speaker is a coil that's also part of the power supply hum filter....

Don't let yourself or others take a problem like this one, a significant hill to get over, and pile little-understood equipment on top of it. Things just get worse.

The phono section shut down when the power was off, but the rest kept working. I didn't check the REC Out because I don't use a tape deck, but I could check it easily enough (tomorrow).

WRT where the volume control is on this amp, it has a dual-trace pad for each input, which is common for Sony and the cause for the PITA aspect of cleaning that particular control- it needs to be disassembled. The sound quality and level didn't change, either. I should have noted that this only happens with equipment that has a "Source Direct" mode and that's how I have tended to use it, but I had forgotten about that aspect of it. I suspect that it would shut down or sound bad if it was in the normal mode. Sorry about that, Chief.

You were describing a stand-alone phono preamp in that last paragraph, right? If so, yes. I haven't been back to the house where I installed the preamp- I'll be there in the next few days and will confirm/deny that it has a level control. I think it does.

When I worked at a stereo store, we had a lot of people bring their receiver in for service because it lit up, but nothing came out. We always plugged it in at the counter and would check a few things, like the protection relay click (if it had that), verify the lights and make sure the controls weren't just dirty. A surprising number came in, working perfectly. One of the main causes was due to the fact that the Tape 1 switch was engaged.

If S/N level is a major criterion, old amps AREN"T better. A great amp from the '70s might have a rated S/N of -63dB for the Phono section (Moving Magnet only) or -80dB for the rest. The amplifier may have been a bit better, in the -90dB range and some were better. One area that IS different is in how they're rated for power. I sold an old Sony Audio Lab integrated amp last year that was rated at 100W/ch, both channels driven, <.01%THD/IM and frequency response of 1Hz-200KHz ±3dB and 20-20KHz +0, -.1dB. I had one of the service techs run it on the B&K distortion analyzer and at rated distortion, both channels driven, the output was 176W/ch.

OTOH, some older equipment had earlier rolloff of the high frequency response, which would contribute to sounding less bright. That, coupled with speakers that used phenolic ring cone tweeters,limited-range horns, older versions of dome tweeters, simple crossovers and designed-in frequency slopes, it's natural that some don't like the newer equipment for it's wide response- they say it sounds 'tinny'. I would ask if they remember anything about the older equipment like the brand, whether they might recognize the front panel, if it had a lot of lights and meters, etc. If they liked it then, it's likely that they'll like it now. There's a lot of good vintage gear out there. Old Marantz is still very good. Avoid the Sansui R-series receivers like the plague- that stuff was crap, it can't be made into non-crap and it will always be crap. The old Sansui was good, but they lost their way before the name was whored out.

Marantz, Parasound and several other current manufacturers' amplifiers are excellent.

I know where I can get an old Bogen and a Stromberg-Carlson PA amp- interested?

Red/Green (Right+/-), White/Blue or Black (Left +/-).

This link is for an Oahu lap steel guitar amp and is similar to the one I have, but mine is older. This one is listed as being from 1939-



The differences between this and mine are:

Mine has #80 rectifier, 6Q7G (Dual diode), 6C8G (Twin triode) and 6L6G (output) tubes, the speaker is hard-wired to the chassis, unlike ALL of the others I have seen, which have an octal plug/receptacle that makes it possible to remove the chassis without the speaker. It also has two huge 30uF filter caps mounted to the chassis and the others have smaller filter caps, mounted internally. I doubt mine was a prototype, but the tube data shows that the 6L6G was patented in '37, so that's about as old as it could be. I haven't seen another with a #80 rectifier, either- all of the others have a 5Y3G or the newer, small bottle.

Recapped, new rectifier, new three-prong power cord and a fuse holder is all it needed- it sounds amazing!.

I have no interest in having any of that stuff, as I'm more than full up right now.

It's interesting that the rectifier is an 80, which is a four-pin tube, while the others, IIRC, have octal plugs. I've never seen a mix of types, but that's just the equipment I've run into.

The best receiver I ever had was a Philco TRF receiver with four stages of RF amplification. Imagine this -- in the thirties, they had made a radio where four RF amplifiers tracked each others' frequencies well enough to select a station with no audible background sound from another station!

What brought that to mind was that none of the tubes had octal sockets. There was the 80, and tubes with five and with six pins.

That radio had a couple of tubes in it indicating that they had been installed as replacements in 1937. I put about 25 feet of wire on its antenna terminal, connected ground to ground, and here in southern California I got WWL in New Orleans and WLS in Chicago. I regularly and easily got KOA in Denver and KOB in Albuquerque; some station in Norman OK; and I heard The Ballad Of Billy Joe for the first time from some dank dark outpost of semi-civilization in the South.

All this radio listening was after midnight on Sundays, when all the local stations were off except for occasional testing.

The 80 matches 5Y3 in performance but another 4 pin rectifier was the 83, which used mercury vapor and had a blue/purple semi opaque glow. I know of one guitar amp that used this briefly in the mid-'50s, but they switched to GZ34/5AR4.

For the 6Q7G and 6C8G, octal sockets aren't enough- they each have a second cathode attached to a button on the top of the tube, with an aluminum sleeve/cover over the whole. tube. I think the use of octal sockets was just due to those being available and it was preferable to use one part, rather than making a specific socket for each tube and then needing to replace it when a tube is discontinued.

I was looking at some old items and one radio (don't remember the brand, but it may have been a Crosley) had tube numbers like 23, 26 and 27.

Amazingly, when I looked on ebay for a replacement rectifier, it was very easy- I bought three of them for $18.50 and the first one I tested worked fine. Using the tube data from the TDSL site, I was able to feel comfortable when I inserted each tube by verifying B+ on each of the previous ones. Then, there was the disappointment in hearing almost nothing when I inserted the cable and touched the tip. I had installed the tubes in the same positions as I found them, but after checking the data, I found that V2 and V3 had been reversed. Once that was corrected, I had a nice, extremely old, working amp.

I think the original owner took the tubes in for testing when the rectifier died and decided that they wouldn't replace it, so they put the tubes back and stuck it in a closet. At some point, someone's kids used it for target practice with their BB gun, but there's minimal damage from that. I don't use it much because I want to keep the original speaker intact- they used hide glue for assembling the cone and it becomes very brittle. It's a Rola K100 and has the field coil you referred to, earlier. It's very noise-free, too.

The field coil is not only a magnet, its inductance is used to lower ripple in the power supply. I think you said there are two filter caps; one is before the coil, the other after. Some speakers of this type also had another winding along with the field coil. AC was fed to this coil with a polarity that helped cancel the varyiations of the magnetic field of the main coil. This coil was called a hum-bucker.

I think Octals were introduced to provide a better way to put the tubes in. The two pins that are larger in diameter, which provide orientation for the pre-octal tubes, sometimes were not enough. One could force a tube in the wrong way.

I forgot the caps on the tops of the tubes -- my TRF receiver had three, I think. I don't remember whether they were plates, or screens, or grids.... That radio died when a bypass or other capacitor failed. I then found that ALL of the bypass and filter caps were built into one steel case about 4 x 4 x 4. It was too late to take it apart and test for capacitance, as one (at least) was dead.

Re the glows of tubes, I've always liked the voltage regulators that glow with a kind of purple color. I've had about a half dozen of them for more than twenty years and just cannot bother to get around to mounting them into a chassis to hang on the wall so I can look at that color. Those tubes, since they do not have a filament, all have numbers starting with zero.

No doubt the hum bucking guitar pickup was inspired by the use of a bucking coil in these speakers. I believe the caps on either side of the coil is called a Pi filter. I'd post a schematic, but I haven't seen one.

This is the site I use for tube info- one of the most comprehensive I have seen-

[Link: tdsl.duncanamps.com]

Here's the layout and schematic for another of my amps- it had a couple of problems last year and after I found/repaired some bad solder joints, I measured for B+ at all of the locations on the schematic- not only were all of the resistors within 5% of the shown values, the B+ was incredibly close, although I'm using a 5R4, not a 5AR4 or GZ34. Not bad, considering it was built in '58.
[Link: ampwares.com]