This joint needs some more vintage hifi

PreCd

mhardy6647:

Thank you for the information. Looks like November is the month for conspiracy even though I do believe the Kennedy theory! Very interesting about that loudness circuit. What is its purpose? I toggle the switch to on and it prevents me from turning the volume up. Maybe the amp has a little problem there.

I will probably purchase a smaller speaker set for the amp if I buy it. The guy is wanting me to shoot him an offer for the amp. In the state its in, which ain't bad, I figured $125 would be fair. The case is dented and the front plate is yellowed which could be cleaned up I assume with the correct cleaning solution.

Can I ask why you would de-mod it back? Would it be to take it back to the original config?

mhardy6647

I have no idea how much diddling was required to reconfigure the operating points to accommodate 6L6s nor how appropriate the output transformer would be for PP 6L6. Maybe all fine, I just don't know. I notice it has what appears to be a 5U4 instead of a 5AR4; if nothing else, I assume that this lowers all of the voltages from the power transformer significantly (maybe 20%? ... a SWAG). It may be absolutely fat and happy running 6L6s... but then again it may be a hack job and putting undue stress on the tubes or the power transformer. A little book research would probably answer all questions but I just ain't savvy enough to know, a priori, if the swap was a good idea or a bad one.

EDIT: Oh, and of course aliens were behind that whole thing in Dallas... they were PO'd about the Area 51 imbroglio, you know? ;-)

EDIT^2: oh... and do you know what's up with that ceramic octal socket back by the output transformer? AFAIK, that's "nonstandard" (i.e., mine doesn't have one)


ST40frontsanstop by mhardy6647, on Flickr

PreCd

mhardy6647:

All good information for me to think about and thank you posting all that you have. I am always open to opinions and suggestions especially those with experience. You are correct about the 5U4 tube. I do not know the advantages/disadvantages of modding the unit to 6L6s but saw where Eico documented the mod. Right now I think a cap replacement program is in order and then go from there. The unit sounds decent but as the gentleman mentioned in one of the links you posted I do want to retain the current physical size of my home. Cap replacement it is!

As for that tube socket in the back I wondered about that too and am surprised to see that yours does not have it. It does not have any connections but did at some point in time. Weird.

Sometime soon I am going to have to plug my Grados into the added headset jack to cop a listen. Interesting little amp and should occupy a piece of my time this winter.

mhardy6647

The ST-40 and ST-70 are sort-of below the radar; I think due to their...umm... idiosyncratic cosmetics.
If the 6L6 conversion was a documented modification, it should be fine. Sorry I besmirched it without grounds! :-)
I don't have an innards shot of the ST-70 handy... but I do have an outards shot ;-)


EICOST70nEPI110C by mhardy6647, on Flickr

Fongolio

A couple of years ago I fully restored a ST-70. New caps, new resistors, loudness mod, along with several other performance mods. The end result was a great sounding unit that I've used daily since. I just blew an original Westinghouse/Eico output tube and am looking for an original but may try some of the new 7591's mentioned above. Here's a link chronicling the rebuild. http://www.polkaudio.com/forums/showthread.php?111045-Eico-ST-70-vintage-tube-integrated-amp-restoration-upgrade&highlight=Eico

mhardy6647

Yes, I should've included that link, too! :-)

Mikey081057

Plugged these into my VR3 LSi 9's and they sound really sweet...Using the pre out of the Marantz 2252B.... The M80 has power to spare and is one sweet sounding amp paired with the Marantz.

Mikey081057

Better pic without my fat head blocking light..

250 Watts (8 ohms) from 20 to 20,000 Hz at no more than 0.003% Total Harmonic Distortion
290 Watts (6 ohms) from 20 to 20,000 Hz at no more than 0.007% Total Harmonic Distortion
330 Watts (4 ohms) from 20 to 20,000 Hz at no more than 0.02% Total Harmonic Distortion
Auto Class A Operating Range, 8 ohms, 30 Watts
Dynamic Power per channel (IHF) 1 khz
8 ohms/6 ohms/4 ohms/2 ohms 380W/480W/640W/850W

scottyboy76

Fat head, nice gear.

Mikey081057

scottyboy76 wrote: »

Fat head, nice gear.

Head like a spackle bucket

TNHNDYMAN

Mikey081057 wrote: »

Better pic without my fat head blocking light..

250 Watts (8 ohms) from 20 to 20,000 Hz at no more than 0.003% Total Harmonic Distortion
290 Watts (6 ohms) from 20 to 20,000 Hz at no more than 0.007% Total Harmonic Distortion
330 Watts (4 ohms) from 20 to 20,000 Hz at no more than 0.02% Total Harmonic Distortion
Auto Class A Operating Range, 8 ohms, 30 Watts
Dynamic Power per channel (IHF) 1 khz
8 ohms/6 ohms/4 ohms/2 ohms 380W/480W/640W/850W

Nice amp. I just sold a M80 and a M85. Still have one M80 and a M70 as well. They have their issues, but when working they definitely have some balls. Love the meters myself.

boston1450

Attachment not found. couldnt see a tuner without a amp. New addition today sounds very nice too

Mikey081057

Sweet i love the yammy look... please add pics when they are lit up too!

cnh

nbrowser wrote: »

awwwww shucks...all this vintage ****...seriously...went back to the used audio store I got my amp from to take a gander...and got a rather large paycheck coming on the weekend has be seriously considering a vintage Marantz 22XX receiver and getting on my hands on a pair of vintage Polk Monitor 5 bookshelf speakers with PRs...just for gits and shiggles...would LOVE an old system to soothe the soul to...

Lots of synergy there! Polk Monitors and 22XX Marantz series.

Nice Yammie pair, Randy! That old look is so "clean" and "timeless". It almost reminds me of what D.T. Suzuki defines as the characteristics of Zen and Japanese Culture in the book of the same name! A fine addition to any literate library!

Enjoy.

cnh

Mikey081057

With all this vintage Marantz talk, my brother ( in Texas) is boxing up tonite a very nice 2385 that he snagged for me at an estate sale...Can't wait to see it... his Iphone pic shows it to be in nice shape and it is fully functional... He knew this was the one I wanted since we were kids, and scooped it up for me. He won't tell me how much until I see and hear it... I am needless to say STOKED and should see it soon... I will post pictures when I can.

cnh

Wow! A 2385! Not a lot of those around and they usually cost an arm and a leg.

Please do post pics. I know what you mean about wanting a piece. For me, since I didn't know about the HIGH POWER units back then, "any" Marantz would have done. I settled on the 2265 below (decades later) which is pretty incredible pushing some Monitor 10As.

I don't have to see you to know that you have a smile that wraps around your entire face!

Enjoy it!

cnh

Mikey081057

cnh wrote: »

Wow! A 2385! Not a lot of those around and they usually cost an arm and a leg.

Please do post pics. I know what you mean about wanting a piece. For me, since I didn't know about the HIGH POWER units back then, "any" Marantz would have done. I settled on the 2265 below (decades later) which is pretty incredible pushing some Monitor 10As.

I don't have to see you to know that you have a smile that wraps around your entire face!

Enjoy it!

cnh

It's on it's way... I will post pics for sure...I go to 3 or 4 estate sales a year, and never come up with anything really good... He comes up with stuff all the time...Not necasarily hi-fi stuff but lots of collectible stuff

There is a Marantz/Polk synergy for sure.

boston1450

Attachment not found.

mhardy6647

is that a CR-1040 or a CR-2040; I am not an expert on the "40" series to be able to tell a priori...

txcoastal1

Nice piece of .........Vintage

Mikey081057

nbrowser wrote: »

Eh just an idea is all DSkip, see if the place I got the amp from can hook the Polk Monitors they have up to the Marantz 2252B they also have for an audition, see what the combo sounds like...then go from there.

I have my 5B's hooked to the 2252B now, and I can say that they never sounded better. They are a little light on the bottom end compared to "newer" 3 way speakers, but nothing that a sub can't cure for sure... I upgraded my tweets to the RDO-194's and just might have Trey make me a set of crossovers and do a bit of a refurb on them.

boston1450

mhardy6647 wrote: »

is that a CR-1040 or a CR-2040; I am not an expert on the "40" series to be able to tell a priori...

thats the 1040. I actually have the 2040 hooked to a pair of sda2b's & it does the job fine:)

Mikey081057

nbrowser wrote: »

Good prices or no ? Canadian store, local to me so no shipping, the 2252B and the Polks in question...

http://www.iavscanada.com/product/marantz-2252b/

And

http://www.iavscanada.com/product/polk-audio-monitor-speakers/

Just looks ripe for a vintage set up...and a perfect waste of Christmas bonus money lol

Don't know how it translates to U.S. $ the 2252 might be a few bucks high, but if it it is fine shape and serviced, not a bad price.

Go for it... It is a nice match...

boston1450

Attachment not found. ....3-350.00 U.S. TOPS on a mint one

boston1450

nbrowser wrote: »

Good prices or no ? Canadian store, local to me so no shipping, the 2252B and the Polks in question...

http://www.iavscanada.com/product/marantz-2252b/

And

http://www.iavscanada.com/product/polk-audio-monitor-speakers/

Just looks ripe for a vintage set up...and a perfect waste of Christmas bonus money lol

The Marantz are built like tanks & pair nicely with Monitor 5 7 10's. You wouldnt be disappointed at all

boston1450

Why the sub?

boston1450

Ive have run 5jr+ 5a peerless 7b 10b's & still cant run bass dial all the way. I was running a Velodyne & ditched it because i never needed it. That was me though. There are lots of powered subwoofers you can run your speakers thru like i did if you wanted to ...mine is 2 channel listening only....FETISH ISNT A BAD THING

cnh

Depends on how the pre-outs on the Marantz are wired. If you have to disconnect the pre-outs from the INS on the Marantz then you would disconnect the pre from the amp section and only the sub would receive the signal.

Since most Polk subs have Line level inputs and outputs, that might be the best way to add a sub. Wire the Marantz to the L/R line level in and run wires from the OUTS to the L/R speakers then use the subs Low Freq knob to set the cut off to the mains?

cnh

Polkersince85

Here's one for you Marantz fans.

http://www.shopgoodwill.com/auctions/Vintage-Marantz-2130-Quartz-Locked-Tuner-Scope-14947308.html

PreCd

My Vintage audio gear. 1986 GFA-545. 1987 SDA2As converted to 2Bs.