Partial restoration of a Marantz 2270
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cortico
Posts: 587
This time sharing a partial restoration of a 2270. This old amps totality deserve being salvaged. Someone was in there before and did a few silly things as replacing just one of the filter caps, the unit was having issues that were resolved after project was complete.
The planed scope was done as follows:
Power supply
-Replace and upgrade mail filter caps, total capacitance was increased.
-Replace all electrolytic capacitors.
-Replace speaker protection relay, this has fixed right channel intermittence.
-Upgrade diodes with fast soft recovery diodes, this reduces background noise.
Used a Omron relay, Nichicon KG main filter and Elna Silmic II caps
Preamp
-Replace all electrolytic capacitors.
Used Elna Silmic II and Panasonic ECQ films, 3.3uf and lower can take film.
Power amp
-Replace all electrolytic and tantalum capacitors.
Phono Board
-Replaced 2SC458 transistors with KSC1845, originals have a tendency to become leaky and add noise.
-Replace all electrolytic and tantalum capacitors.
-Upgraded existing diodes
-New vellum paper
-New incandescent bulbs
-New power switch and safety cap
Before:
After:
Top
Bottom
Power supply:
Before:
After
These are huge:
Pre amp, access was somewhat difficult:
Before:
After:
Power amp, the access was also not easy:
Phono amp
Some of the part replaced:
The planed scope was done as follows:
Power supply
-Replace and upgrade mail filter caps, total capacitance was increased.
-Replace all electrolytic capacitors.
-Replace speaker protection relay, this has fixed right channel intermittence.
-Upgrade diodes with fast soft recovery diodes, this reduces background noise.
Used a Omron relay, Nichicon KG main filter and Elna Silmic II caps
Preamp
-Replace all electrolytic capacitors.
Used Elna Silmic II and Panasonic ECQ films, 3.3uf and lower can take film.
Power amp
-Replace all electrolytic and tantalum capacitors.
Phono Board
-Replaced 2SC458 transistors with KSC1845, originals have a tendency to become leaky and add noise.
-Replace all electrolytic and tantalum capacitors.
-Upgraded existing diodes
-New vellum paper
-New incandescent bulbs
-New power switch and safety cap
Before:
After:
Top
Bottom
Power supply:
Before:
After
These are huge:
Pre amp, access was somewhat difficult:
Before:
After:
Power amp, the access was also not easy:
Phono amp
Some of the part replaced:
Post edited by cortico on
Comments
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Wow. I always have loved the look of vintage amplifiers. I think this one is especially pretty. Nice job!
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Thanks mlistens0, They look good and they sounds very nice as well.
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Very nice work!Home Theater/2 Channel:
Front: SDA-2ATL forum.polkaudio.com/discussion/143984/my-2as-finally-finished-almost/p1
Center: Custom Built forum.polkaudio.com/discussion/150760/my-center-channel-project/p1
Surrounds & Rears: Custom Built forum.polkaudio.com/discussion/151647/my-surround-project/p1
Sonicaps, Mills, RDO-194s-198s, Dynamat, Hurricane Nuts, Blackhole5
Pioneer Elite VSX-72TXV, Carver PM-600, SVS PB2-Plus Subwoofer
dhsspeakerservice.com/ -
The 2270 was (is) a very special piece -- it would be interesting to hear (so to speak) how you think it compares to the 1060 amplifier you "did"!
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Thank you westmassguy! It’s great to have a nice complement from a talented person!westmassguy wrote: »Very nice work!mhardy6647 wrote: »The 2270 was (is) a very special piece -- it would be interesting to hear (so to speak) how you think it compares to the 1060 amplifier you "did"!
mhardy6647, the Model 2270 is a beast in every sense, sounds more punchy, has a more coherent frequency response, has the Marantz vibe in it but is precise and sounds more dynamic.
Probably, I think it’s conservatly rated at 75w per channel, probably to much power for my listening space, It has to be fairly loud to sound its best. I can’t dial it in at low listening volumes.
Does it sound nuts if I pick the little 1060? I need to admit that I am very partial to the amp I just rebuilt, but to my hears, now sonically supersedes the 2270. It also seems to be a better fit to my speakers, room and listening level.
With that being said, I am fond of the capacitor output coupled designs’ typical sound “coloration” in the sound, I leaned that it’s a flaw present in a form of pleasent distortion that I perceive as a warm and velvety sound.
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Fantastic job!!!
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Thanks Conradicles!
It’s curious that Marantz lower end units as the Model 1060 shared the same pre amp as the TOTL:
Original 2270 pre amplifier board:
Rebuilt 1060 pre amplifier board:
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It's common, more than you think to share modules within units of the same vintage, even with large price differences. Lots of old units I used to sell and too often, fix, back in the mid 70's had the same boards for the tuner, preamp/phono. The amp sections were where the big differences were, along with the PS and size/weight of the unit. The main problems back then were bad solder joints and heat cooking caps and sometimes ICs. The cooking of ICs seems to have made a comeback in some Denon and other similar HT receivers with the transformer partially covered by a board filled with temp sensitive parts. NOT a good idea.
This is a Marantz SR5012, and I don't see this ending well at all:
https://cdn3.volusion.com/exvfd.rdrcz/v/vspfiles/photos/SR-5012-5.jpgCable atheist: They're just trying to get your money like a TV preacher!
Vinyl system: I'm long done with the snap, crackle, and pop.
