Author Topic: Sylvania Maestro SC919K  (Read 1191 times)

Motorola Minion

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Sylvania Maestro SC919K
« on: January 04, 2017, 03:03:40 PM »
I almost walked past this, mostly because Early American is what you often see at my local Habitat Restore. French provincial runs a close second when it comes to the higher-end consoles found here of any given make.
Its likely that the folks who paid more $$$, primarily had this kind of taste.

After scooping up some cheap unused "steel city" outlet and switch boxes for my house addition, I circled back and lifted the lid - in the record bin was an operation manual, hang tag, schematic of both amp and receiver chassis and the brochure page attached below. It was reported as being dead and the Dual 1009 was missing but I have one for it :D

What I found interesting is the Acoustic compensator switch that has three settings based on the room dimensions.

I later donated the '68 Sylvania to H4H, which I added an Ipod cord to.
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Dave

Motorola Minion

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Re: Sylvania Maestro SC919K
« Reply #1 on: January 10, 2017, 12:45:55 PM »
I placed the Amp and Pre-amp tuner factory schematics in the "downloads" section, which requires a log-in to see all the posted schematics
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Dave

chazglenn3

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Re: Sylvania Maestro SC919K
« Reply #2 on: September 28, 2018, 09:46:21 AM »
Hey Dave;

Do you remember if this unit put out a lot of power, maybe similar to the Zenith high power units like the Z966?
Charles
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Motorola Minion

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Re: Sylvania Maestro SC919K
« Reply #3 on: October 01, 2018, 08:53:31 AM »
I am pretty sure they both used RCA's  ;) transistors  :-\ and may have each claimed 200-300 watts ???.

The was the TOTL Sylvania as far as the vintage Sylvania website is concerned. I have a Zenith Z966 and the sales lit claims 320 watts. If that is an IHF figure, its the highest peak "quotable" and was not anything like the more reasonable numbers from Magnavox and RCA.

Some day I will have both these SS units recapped and pots cleaned, so I can compare them.
All they really need is time and parts I already have, unless there is a speaker issue.
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Dave

SeniorSteve

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Re: Sylvania Maestro SC919K
« Reply #4 on: October 01, 2018, 04:53:51 PM »
Yes they all used germanium output transistors (Zenith, Sylvania and most of the major console manufacturers up through the late 60's).  The SC919 had the top of the line Sylvania power amplifier which used a split power supply on the output transistors and no coupling capacitor.  It potentially had a voltage swing on the output of + or - 45 volts if perfect.  I have a Sylvania component receiver (RS4744) that has + and - 50 volt power supplies and is rated at 60 watts RMS per channel, so I would guess the console is slightly less, maybe about 50-55 watts RMS per channel, and in the mid 60's that was a LOT of power.

The Zenith B966 had a single power supply of around 65 volts so split that in half and you have about a + and - 32 volt supply to work with.  If perfect, you could potentially get about 25-30 watts RMS power per channel.  Still, because the speakers were matched to the amplifier, they really pushed out the sound.  I have a Zenith MM 2670 console with a 55 volt single power supply which in 1964 was rated at 320watts - I believe IHF.  In actuality, I believe it really only puts out about 20-25 watts maximum per channel, but sounds incredible.  Unless you are expecting window shattering volumes, don't get bent on the wattage rating, the efficiency of the speakers and other factors outweighed the pure power rating.

Consoles from the very late 50's through the 60's are the ones I really like to work on as you can get almost all of the parts for them easily.  That is except custom items like dial glass or knobs or other such items.

Motorola Minion, when you start working on your Sylvania, be very careful with the dial glass, I thought a quick wipe down would not harm it, but was unpleasantly surprised when it did - worst of all it was not mine to disfigure.  The dial glass was very similar to the SC919, but it had the log scale between the AM and FM number markings instead of the metal divider.  If I could only go back in time with the new knowledge.  The thing I liked about the Sylvania was they used a Dual record changer in their top of the line sets with magnetic cartridges, and I think those were some of the best changers made at the time, even now they do get a good price for working models as they are fairly gentle on records (for a changer).

Steve