Vintage Amp Connection

[highfigh]

I'm wanting to use my main front speakers in my current setup for music listening through the Eico ST-40. Is there an easy way to do this? In Zone 2 I would need a separate pair of speakers?

The Eico won't output the power the Marantz does, nor does its sound have the same high frequency range, so before you make it semi-permanent, I would recommend just listening to it with the analog out from a CD player connected to its input (pick one- other than the phono input, they're all basically the same), to get an idea of how it sounds. It won't be the same, but you may like it. If you do, great- THEN, find an easy way to use it, whether with its own speakers (not a terrible thing) or by using the same as the Marantz is connected to but the one thing you need to do is shut the equipment off EVERY time you swap. If you want the EICO to be at the center of a vintage system, you can use the output from the Marantz- you won't need to make any changes after it's connected, but you will need to activate that zone and switch the input to allow hearing it through the EICO. If you use a DVD player (CD or BD player would be the same) and it has analog outputs that you never use, you can connect those to the EICO and not need to change anything but if you play the Marantz using the digital output from the disc player, you need to realize that you'll hear a slight delay when both are playing.

 

[highfigh]

I never shopped for one. I had the opportunity to take this home to try and I was hooked. Actually he asked me a couple times to come get it. The real test is when I connect it to main fronts. I may end up using this as a stand alone system just for music or get a speaker switch box. Not only is it nostalgic and sounds great it's a fun project and something new. I own 2 tube guitar amps and to me they sound better than any solid state amps I've ever tried. The cool thing about tubes is you can have them repaired. Nobody wants to fool with the solid state stuff and it's almost disposable. I mean how cool is it to play music thru something that was made in 1960? Not to mention that he is selling it to me for just what he has in it. If anything it will be a good investment.

You might be surprised by checking into who repairs what- most cities have people who miss the old days as much as anyone and some of them actually CAN repair this stuff when it breaks, but the digital circuits may be a place where they draw the line, especially with the parts that are disco'd and can't be cross-referenced. Analog parts are usually easy enough unless they were originally proprietary, like VFets and some other output transistors.

 

[Eppie]

Personally I can't imagine wanting the tube amp mixed into the system at all....reminds me why I don't want to fuss with tubes.

Reminds me that I need to do a restoration on my Ampeg V4B bass amp. It's all original so there are bound to be some leaky caps and shoddy resisters in there. I have some spare tubes at least. Saving that project for when the basement wall unit is finally finished.

 

[highfigh]

Reminds me that I need to do a restoration on my Ampeg V4B bass amp. It's all original so there are bound to be some leaky caps and shoddy resisters in there. I have some spare tubes at least. Saving that project for when the basement wall unit is finally finished.

If you have bad resistors, you should see out of range voltage at some test points. Some may be darkened from heat, others may cause problems with tube lifespan or red-plating, possibly blowing the fuse. The caps aren't expensive and it's not a stretch to think that some are bad because of the age, especially if it has been sitting for a long time but that's no guarantee- many old amps work fine with the original parts and I recently sold a Magnatone that worked great with all original except for maybe two tubes. No hum, no weird harmonics.

 

[Eppie]

If you have bad resistors, you should see out of range voltage at some test points. Some may be darkened from heat, others may cause problems with tube lifespan or red-plating, possibly blowing the fuse. The caps aren't expensive and it's not a stretch to think that some are bad because of the age, especially if it has been sitting for a long time but that's no guarantee- many old amps work fine with the original parts and I recently sold a Magnatone that worked great with all original except for maybe two tubes. No hum, no weird harmonics.

I haven't worked a lot with tube amps, but I spent a great deal of time last year watching restoration videos on Mr Carlson's Lab Youtube channel (fellow Canadian). This guy is one of the best at what he does and has a really pleasant speaking voice which makes the lengthy videos easier to watch all the way through. Lots of great tips on things to look out for when working with older tube gear. I learned a lot.

I restored a Williams pinball machine from the late '70s back in 2009. The resistors on the right side of the PCB were mounted close to the surface and almost destroyed the PCB. Luckily I managed to salvage the copper tracks and replaced them all leaving a proper air gap. A couple zener diodes had gone on the power supply and some of the filter caps were bad. Battery holder for the memory was destroyed due to battery leakage, so I replaced that. A number of logic ICs had bad gates, so I replaced them with IC sockets and new chips for easier maintenance later. Fixed a few mechanical issues as well with the bumpers, targets and solenoids. I've only had the occasional light bulb burn out since then.

 

[cpp]

I've always wanted to listen to this rare gem.

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[Eppie]

I've always wanted to listen to this rare gem.

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When I first heard the JBL Summits they were connected to a Harmon Kardon Citation 16, with those pretty LED meters. Would be nice to get a hold of one of those for sh!ts and giggles.