Vintage Marantz Receiver - Tone-defining component

[Yoku-San]

I have a Marantz 2238B receiver which I like or liked very much and would like to keep. I gave it to an experienced technician near my hometown who serviced it last month. For the time that it was in service, I bought an Aiyima A07 for my Polk R200 speakers and was surprised and somewhat irritated how good the combination sounded compared to my old Marantz.

Back from service the Marantz sounds quite nice and I would like to keep it as it has a good phono stage, nice tuner section etc.

I have tried to circumvent the Marantz power section by using the Pre-Out and going through the A07 amplifier section. However A/B switching between the A07 amplifier or the Marantz Amplifier section did not reveal major differences in sound.

Is it therefore correct that the Preamp section of the vintage Marantz receiver is the major tone-defining component producing the warm signature with somewhat muddy bass?

I am really confused if I should get rid of my serviced Marantz and buy something like the IOM I250.

 

[mhardy6647]

Empirically, it seems so.

What did your experience technician do to it when he/she/they "serviced" it? I you still have 45-ish year old capacitors in the (preamp) signal path, warm and muddy is a pretty likely symptom, I'd opine. The power amp appears to be direct coupled (FWIW).

 

[Yoku-San]

Empirically, it seems so.

What did your experience technician do to it when he/she/they "serviced" it? I you still have 45-ish year old capacitors in the (preamp) signal path, warm and muddy is a pretty likely symptom, I'd opine. The power amp appears to be direct coupled (FWIW).

Well, I asked him if they recapped it but he said they measure all components and circuits and only replace something if it is defective. And no Caps had to be replaced. But they had to solder some broken connection of the transformer (I had not noticed any defect of the amp). So I guess they soldered, cleaned and measured a lot for the nearly 300€ I paid for the service. I had the receiver already serviced like 15 years ago in another place (other city). Maybe they did a recapping then, I do not remember.

 

[restorer-john]

Is it therefore correct that the Preamp section of the vintage Marantz receiver is the major tone-defining component producing the warm signature with somewhat muddy bass?

Yes.

The preamp stages of contribute most of the sonic signature of the 1970-1980s Marantz amps and receivers. The power stages less so, but they also contribute a typical roll-off at each end of the spectrum.

My testing has even shown some Marantz models compensated in the preamp for the deficiencies of the power stage, even at 'flat' settings.

Find a technician who can run frequency response plots on the pre and power stages at various levels and you will soon discover where those audible differences are coming from. Don't focus on 'capacitors' causing what you think you hear. If they are within spec (most likely), the sonic signature will be very close to what Marantz designed in the first place.

The 2238B was a about middle of the range, and its performance and sound are commensurate. The more expensive receivers got flatter repsonses, more power and more features.

 

[DVDdoug]

the major tone-defining component producing the warm signature with somewhat muddy bass?

Maybe a "dumb question" but does it have a "loudness" switch? Is it working? Do you hear a difference when you switch it on/off, especially at lower volumes?

 

[mhardy6647]

I absolutely defer to @restorer-john on this topic! He has far, far more, and more relevant experience with these (i.e., Superscope-era Marantz receivers) than do I.

 

[Chrispy]

Maybe a "dumb question" but does it have a "loudness" switch? Is it working? Do you hear a difference when you switch it on/off, especially at lower volumes?

One of the better features of the Marantz receivers of this era (altho not particularly noteworthy otherwise IMO) was the loudness switch to enhance bass/treble at lower volumes, altho believe was fixed value rather than varying with volume. I had a 2270 back then, don't miss it, certainly wouldn't pay to have it refurbished for more than its original cost (but it died early on and didn't see any point in having it "fixed").