In love with capacitor coupled output sound

cortico · February 2018

I have been bored lately, when that happens I tend pop out here

This time the story is, a while ago I got a Marantz 1060 from the mid 70s, sold a while after when I moved to a different home.

There is something euphoric on this amps, I very well know that is just distortion and coloration from a an early design being picked by my brain as a lush velvety sound I can listed for days. The true is that I have missed it to bits ever since.

So, recently I got another 1060 on that auction site. It’s very clean and 99% original, the volume pot which was replaced at some point but it serves the purpose and will be easy to source the original.

This 1060 sounds so cool to my hears to a point I don’t want to recapped. This is a nonsense but the trues is that I don't want to touch it. A recap will certainly change things a bit, maybe for better but that's not the goal in this case. I experienced a different flavor when I recapped the the bigger cousin 2270, especially after I hit the preamp-tone board.

So, I moved ahead and got second 1060, which I am planing to recap/upgrade and then AB with the original. I guess, I am steeping away of the upgrade idea. Many folks like to bump up power supply capacitance to increase reserve, better low frequency response and more headroom. Others don't it's controversial...

I do actually intend to keep the values close to original, with the exception of the main filter capacitor, I am bumping from 4700uf to 6800uf just because I found a Jensen 4 pole for half the price.

These for pole caps look a bit more tricky to wire but I understand that the + from rectifier goes to the "+ in," then the the amp board wire comes from "+ out." All the ground wires go to "-in," and the "- out" goes to that ground strap", seems easy.

The coupling caps will remain 3000uf (original) or 4700uf max because the physical size matches existing braces, planing to use Jensen here as well.

In addition to main filter and coupling, on the first approach, I will also replace all electrolytic on power supply board and all the local power supply filters, I have used Elna Silmic II on my 2270 but looking for something different and cool probably "Audio Note Kaisei lytics"... as they are inspired on the famous Black Gates, these are found in several pieces of Parasound gear and i dig that sound.

Sorry for any confusion I am typing on a foreign language...

Any input or advice is welcome,

msg · February 2018

No advice, but I enjoy your tinkering projects, so I'll be following along. Of course, I'm curious to hear the AB comparison results, because, yes, I've heard conflicting perspectives on recapping these lushy old Marantz units.

mhardy6647 · February 2018

That's a pretty 1060.
There're a couple of them here -- but they're kind of tired.

If you like capacitor coupled outputs -- you should try a transformer coupled amp sometime

Or a semi-complementary cap-coupled amp like an HH Scott 260/LK-60B.

cortico · February 2018

mhardy6647 wrote: »

That's a pretty 1060.
There're a couple of them here -- but they're kind of tired.

If you like capacitor coupled outputs -- you should try a transformer coupled amp sometime

Or a semi-complementary cap-coupled amp like an HH Scott 260/LK-60B.

This is something I am curious about!

SCompRacer · February 2018

Does it output that much DC that you need AC coupling?

My discrete output DAC I/V stage has common mode DC. For those who don't know, common mode is DC between balanced ground and negative balanced, and ground and positive balanced. (DC can be nulled between pos and neg balanced). Enough DC that it will shut my old Krell KSA-250 down.

I chose to run with balanced ground lifted rather than run couplers.

Viking64 · February 2018

mhardy6647 wrote: »

That's a pretty 1060.
There're a couple of them here -- but they're kind of tired.

If you like capacitor coupled outputs -- you should try a transformer coupled amp sometime

Or a semi-complementary cap-coupled amp like an HH Scott 260/LK-60B.

Scott complimented my pretty semi when I was excited over my tired transformer coupled capacitor output amp.

mhardy6647 · February 2018

SCompRacer wrote: »

Does it output that much DC that you need AC coupling?

My discrete output DAC I/V stage has common mode DC. For those who don't know, common mode is DC between balanced ground and negative balanced, and ground and positive balanced. (DC can be nulled between pos and neg balanced). Enough DC that it will shut my old Krell KSA-250 down.

I chose to run with balanced ground lifted rather than run couplers.

Yeah, it doesn't have a fully differential amplifier -- both halves of the push-pull outputs ride on one side of zero volts DC, so there is a significant DC offset on the power transistors' output. The filter capacitor removes the DC. It's a pretty brute force approach but it was necessary in the early days of transistor amplifiers (due mostly to technological limitations of making transistors). EDIT: Later cap-coupled amplifiers represent a design with a single DC output from the power supply -- which, arguably, may have been done to manage costs(?).

The "cost" of the coupling capacitor, of course, is a limit to the LF response of the amplifier (which is probably pretty negligible with a large value coupling cap) and frequency dependent phase shift above the cutoff frequency for the cap coupled circuit. I imagine that the square wave performance of a cap-coupled soiled state amplifier is pretty ugly -- but I don't know that for a fact.

DC amplifiers were - and are - scary. If anything goes wrong, anything up to the full rail voltage can go straight to one's loudspeakers. That rarely ends well

PS ... and then you have output transformerless (OTL) vacuum tube amps

Anything goes
wrong there, and the plate voltage (several hundred volts DC) goes to the speakers. Oy.

mhardy6647 · February 2018

BTW, here's why there are two working but "unrestored" 1060s sitting around at my house...

Why do they put so danged many electrolytics in them dang soiled state amps?!
?

source: http://electricblog.justinis.com/2015/01/marantz-1060-restoration.html

Oh, the OP probably already has this, but the SM for the 1060 is available from multiple sources:
http://akdatabase.org/AKview/albums/Marantz/Marantz 1060 Service.pdf

msg · February 2018

Those caps look like people standing in different positions. Some even have pants on. Clamdiggers, I think. One or two are bursting for the toilet. Fourth across the top row's caught my eye. I think I'll ask her out...

Viking64 · February 2018

msg wrote: »

Fourth across the top row's caught my eye. I think I'll ask her out...

The second across the top looks like she might be more....accommodating.

mhardy6647 · February 2018

I know youse guyses are really looking for the bipolar capacitors -- not that there's anything wrong with that.

cortico · February 2018

mhardy6647 wrote: »

BTW, here's why there are two working but "unrestored" 1060s sitting around at my house...

Why do they put so danged many electrolytics in them dang soiled state amps?!
?

source: http://electricblog.justinis.com/2015/01/marantz-1060-restoration.html

Oh, the OP probably already has this, but the SM for the 1060 is available from multiple sources:
http://akdatabase.org/AKview/albums/Marantz/Marantz 1060 Service.pdf

Thanks for your contribution.

Yes, I have downloaded the service manual. There's a ton of very useful restoration threads and very knowledgeable folks willing to help threads on AK as well.

SCompRacer · February 2018

I have some resistor pictures but they are not G rated.

This old Krell KSL pre with phono board had a few caps.

mhardy6647 · February 2018

well, a phono preamp needs a few for equalization

tonyb · February 2018

Speaking of HH Scott, here's a purdy clean one local to me...

https://chicago.craigslist.org/nch/ele/d/scott-480a-integratedamplifier/6478067197.html

mhardy6647 · February 2018

^^^ Not bad stuff at all -- even that late in the brand name's long (and somewhat checkered) legacy!

tonyb · February 2018

mhardy6647 wrote: »

^^^ Not bad stuff at all -- even that late in the brand name's long (and somewhat checkered) legacy!

Yep, even their soiled state receivers had a very tube-ish sound to them, and powerful. The old stuff, newer stuff was dumpster diver material.

That vintage sound, like the older Marantz's, Sansui's, Scott.....very addicting. Not the most transparent or detailed sound, but pleasurable to listen to for hours on end. Makes one wonder why we keep chasing this higher end banana in audio.

Tony M · February 2018

They should just remake these amps and receivers using the old schematics but with newer Caps and Resistor options. Kind of like what Volkswagon did with the BUG. I like the newer bugs design a lot too.

mhardy6647 · February 2018

Tony M wrote: »

They should just remake these amps and receivers using the old schematics but with newer Caps and Resistor options. Kind of like what Volkswagon did with the BUG. I like the newer bugs design a lot too.

I think the latter day Beetle was a tad different than the original

mhardy6647 · February 2018

tonyb wrote: »

mhardy6647 wrote: »

^^^ Not bad stuff at all -- even that late in the brand name's long (and somewhat checkered) legacy!

Yep, even their soiled state receivers had a very tube-ish sound to them, and powerful. The old stuff, newer stuff was dumpster diver material.

That vintage sound, like the older Marantz's, Sansui's, Scott.....very addicting. Not the most transparent or detailed sound, but pleasurable to listen to for hours on end. Makes one wonder why we keep chasing this higher end banana in audio.

My LK-60B

004 by Mark Hardy, on Flickr

I did actually have the discipline to pass along a couple of ss Scott receivers to others (believe it or not)!

Scott 342C by Mark Hardy, on Flickr

Scott 342C innards sideview by Mark Hardy, on Flickr

Scott348 innards by Mark Hardy, on Flickr

Early ss hifi was built sort of like vacuum tube hardware, with socketed transistors, e.g. "Modular" construction was also a fad (TVs, too) -- these Scotts are relatively "modular" -- and very nicely built.

Oh, I do still have a Scott 357, though, come to think of it

357frontal by Mark Hardy, on Flickr

The FM tuners in all three of those early, US-made HH Scott receivers are excellent by any standard (audio- and radio-wise).

tonyb · February 2018

Show off...lol

Nice Scott receiver here too for only 160...

https://chicago.craigslist.org/nch/ele/d/vintage-hh-scott-377b/6472875543.html

cortico · February 2018

tonyb wrote: »

That vintage sound, like the older Marantz's, Sansui's, Scott.....very addicting. Not the most transparent or detailed sound, but pleasurable to listen to for hours on end. Makes one wonder why we keep chasing this higher end banana in audio.

Tony M wrote: »

They should just remake these amps and receivers using the old schematics but with newer Caps and Resistor options. Kind of like what Volkswagon did with the BUG. I like the newer bugs design a lot too.

Agreed, they do sound pleasant, as the man said:

If it sounds good and measures bad, -- you've measured the wrong thing." Daniel Von Recklinghausen

People go really nuts restoring this old amps, almost everything with exception of a few critical parts as output transistors and some film capacitors. I have seen circuit board replicas getting re-populated with all new high-grade components.

I don't get why they aren't built like this anymore. It seems that consumer's trend now is to have convenience, extra features and seeking to upgrade gear every couple years in lieu of and longevity...

A nice rebuilt on the link below:
http://audiokarma.org/forums/index.php?threads/my-try-at-a-really-nice-rebuild-marantz-1060.489269/

tonyb · February 2018

"I don't get why they aren't built like this anymore. It seems that consumer's trend now is to have convenience, extra features and seeking to upgrade gear every couple years in lieu of and longevity..."

You think consumers like buying gear every few years ? It's called built in obsolesce, and just about every maker of consumer goods has caught that bug. Can't make too much money by selling a product that last 20 years.

That's why vintage is in demand and some sink good coin into refurbishing them. They may last another 20-30 years. To make something like that, today, you'd pay 3-4-5 k for.

The higher end stuff today is built pretty good. I always suggest to look at yesterdays high end stuff, Like B&k, Classe, Cary, ML, Proceed....their outdated processors and their amps are pretty darn good.

tonyb · February 2018

Ya have to remember too, much of that vintage sound we all like, came from using all those vintage transistors, caps, etc. When you redo these things, they may lose some of that luster. Only thing you really can do is replace with the closest values you can find.

I've read up on a lot of vintage threads in regards to refurbishing these old receivers/amps. Lots of good suggestions for brands that best match that vintage sound. Google up your specific brand and model, the internet is great for some things.

mhardy6647 · February 2018

tonyb wrote: »

Show off...lol

Yup (although "show off" is a term not many would apply to old junk like that...

Nice Scott receiver here too for only 160...

https://chicago.craigslist.org/nch/ele/d/vintage-hh-scott-377b/6472875543.html

whoa, that is one that's not seen every day... it is a good thing I don't live out there or, even at that price, it might follow me home

(from the ad in question, reproduced here for posterity

)

mhardy6647 · February 2018

cortico wrote: »

...

Agreed, they do sound pleasant, as the man said:

If it sounds good and measures bad, -- you've measured the wrong thing." Daniel Von Recklinghausen

...

heh -- speaking of H.H. Scott

http://hhscott.com/vonrecklinghausen.htm

cortico · February 2018

tonyb wrote: »

Ya have to remember too, much of that vintage sound we all like, came from using all those vintage transistors, caps, etc. When you redo these things, they may lose some of that luster. Only thing you really can do is replace with the closest values you can find.

I've read up on a lot of vintage threads in regards to refurbishing these old receivers/amps. Lots of good suggestions for brands that best match that vintage sound. Google up your specific brand and model, the internet is great for some things.

When I recapped a Marantz 2270 it ended up sounding pleasant, but definitely not the same I sound I recall before capping. I can make sound closer by twinking the tone controls but it's not the same when Bass, mid and treble is set at noon.

Nostalgy apart, some original components have a specific voice that adds to that typical 70s Marantz coloration thing, replacing them with correct value and voltage may not do it.

Without wanting to digress, guitarists are way more conservative than Hi-Fi hobbyists, the procedure is regrated by the principle "it is not broken don't fix it" no one will ever think of replacing original tone capacitors those noisy brown carbon comp resistors on a vintage guitar amp as they contribute to its mojo.

It would be interesting to AB the unmolested 1060 vs recaped 1060.

agfrost · February 2018

SCompRacer wrote: »

I have some resistor pictures but they are not G rated.

This old Krell KSL pre with phono board had a few caps.

That should be the centerpiece of someone's rig...

mhardy6647 · February 2018

nbrowser wrote: »

mhardy6647 wrote: »

Tony M wrote: »

They should just remake these amps and receivers using the old schematics but with newer Caps and Resistor options. Kind of like what Volkswagon did with the BUG. I like the newer bugs design a lot too.

I think the latter day Beetle was a tad different than the original

Yeah...too modern lookin and the put the engine in the wrong end and also made the wrong end the drive end...ugh.

egg-zackly

Maybe the latter-day Beetles have heaters that work, though? I dunno

mhardy6647 · February 2018

agfrost wrote: »

SCompRacer wrote: »

I have some resistor pictures but they are not G rated.

This old Krell KSL pre with phono board had a few caps.

That should be the centerpiece of someone's rig...

Well, yeah, maybe -- but I am not sure I'd want my signal goin' through all of that stuff on any given day.

cortico · February 2018

That Krell layout look pretty clean, though!

In love with capacitor coupled output sound

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In love with capacitor coupled output sound

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