Realistic 42-2101A Review (Vintage Phono Stage)

[amirm]

This is a review and detailed measurements of the Realistic (Radio Shack) model 42-2101A phono preamplifier. It is on kind loan from a member and originally cost US $20 but I now I see a used one on ebay for $35.

The 42-2101 has the basic look of a lot of Radio Shack audio products:

The thing that really got me was the text on the back:

Made in Japan for Radio Shack? Man, those were the days that Japan could make such products and still make money. Golden era of hi-fi to be sure....

Interesting that power supply is built-in. Everything today in this price range would have an external one. They went through UL certification and all.

Realistic 42-2101A Measurements
As usual we start with our dashboard:

Inclusion of AC power supply inside the unit is likely the cause of mains noise in there although some of the spikes are post rectification. Distortion is low at -90 dB. It is the power supply noise that knocks the SINAD massively down to 55 to 61 dB. No amount of grounding setup made a difference.

Frequency response is key to the "sound" of a phono stage so let's see how it does there:

Looks like they had a good intention there with the rumble filter, cutting out the low frequencies. Alas, that is causing that peaking so may make the sound bass heavy.

Last test I ran was the input level vs output distortion+noise:

As noted, there is good bit of headroom before the unit clips.

Conclusions
If you are feeling nostalgic, I guess this phono preamplifier makes a good target. Otherwise, it is not something I would recommend.

------------
As always, questions, comments, recommendations, etc. are welcome.

Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

 

[sweetchaos]

Mad in Japan

 

[Doodski]

Hmmz... Reminds of the last days of Radio Shack in Canada in the early to mid 80's. I bought a very nice Radio Shack scientific calculator that was quit rare and expensive for the day and it worked wonderfully. I gave it to my drafting instructor when I finished that study because I bought the last one at the Radio Shack store and he wanted to buy one but couldn't. I never bought any stereo gear from Radio Shack but I used one for a community dance we had in the town hall and it worked well, took whatever we forced it to do and it survived even though we burned the dust out of it. It was a great store to have in a small little city and we all went there to see what was new and exciting. I miss Radio Shack because it had electronic components, had lots of neat stuff and new models all the time. I bought my fist electronics kit there a analogue multimeter that I assembled for my grade 9 electronics class. I'm sure the Minimus speakers recall memories for many peeps.

 

[amirm]

The best thing about Radio Shack was that they had stores even in smallest towns. So if you needed something, you could drive and get it. Even today that would be a good resource to have. Shame they closed up.

 

[restorer-john]

The unit was made in August 1981, so it's nearly 40 years old. The 2101A came in late 1979 and ran for many years, although IIRC, the later ones came out of Taiwan.

Here's the specs:

And the schematic:

The overload spec seems to be spot on at 1%/100mV.

 

[Doodski]

The unit was made in August 1981, so it's nearly 40 years old. The 2101A came in late 1979 and ran for many years, although IIRC, the later ones came out of Taiwan.

Here's the specs:
View attachment 107707
And the schematic:
View attachment 107708

The overload spec seems to be spot on at 1%/100mV.

It appears the actual unit equals or surpasses the signal to noise and the frequency response.

 

[wwenze]

Can I say that...

For this kind of price so long ago...

This kind of performance is...

...Realistic...?

 

[Nango]

Waste of time this article. Again.

 

[3125b]

I mean ... some modern and waayy more expensive phono preamps don't perform better (*cough* Chord Huei *cough*).

 

[Frank Dernie]

Made in Japan for Radio Shack? Man, those were the days that Japan could make such products and still make money.

I am of an age where I remember Japan as a super cheap supplier of tatty copies, a bit like the image China is ascending from now.
In the UK when I was an apprentice "japped" was slang for making a bodged copy.
How things have changed, the epitome of quality engineering most can't afford now!

 

[BDWoody]

Waste of time this article. Again.

Waste of time to make a post like that.

Again.

 

[anmpr1]

I am of an age where I remember Japan as a super cheap supplier of tatty copies, a bit like the image China is ascending from now. In the UK when I was an apprentice "japped" was slang for making a bodged copy. How things have changed, the epitome of quality engineering most can't afford now!

When the average citizen cannot afford items that are made in their own country, it is telling. Or when items cannot be made in their own country because the very cost of manufacture prices them out of reach of the average citizen.

When I was a kid Japanese electronic products were considered 'junk'. Throw-away plastic transistor radios and such. The change in consumer electronics happened in the late '60s. By the mid to late '70s the Japanese had pretty much the lion's share of mainstream consumer electronics. For the price of a Dyna kit you could buy an assembled, made in Japan product with better fit and finish, more features, better specs, and more consistent operation. Now anything actually made in Japan is probably going to cost you McIntosh dollars.

 

[SIY]

View attachment 107708

The overload spec seems to be spot on at 1%/100mV.

The major problem with these kind of circuits was a highly nonlinear input impedance (which of course this measurement suite doesn't look at). That was the thing which made products like Advent and dB and Apt-Holman actually sound better, they designed their input stages to have a constant impedance.

 

[beagleman]

I am willing to bet, that more people actually have owned this item than all the "audiophile" pre-amps combined. SO yes this is quite informative!

 

[anmpr1]

I am willing to bet, that more people actually have owned this item than all the "audiophile" pre-amps combined. SO yes this is quite informative!

This (or one like it) was my first phono preamp. I replaced a ceramic cartridge on my Garrard Model 30 with a Shure M44. I bought a RS phono stage to use with the Shure. This was in the late '60s. As a kid, and for the price, it was a definite improvement to what I had.

 

[Helicopter]

Thanks Amir. I am glad to see acceptable performance here. I have a bunch of Realistic gear because I am nostalgic about the cool store we had growing up in Alaska.

 

[Hiten]

Can we safely say that 40 year old preamp didn't required replacng capacitors ? OR replacing them would have changed any measurements ?
Thanks for the review.
Regards.

 

[abdo123]

Can we safely say that 40 year old preamp didn't required replacng capacitors ? OR replacing them would have changed any measurements ?
Thanks for the review.
Regards.

This is a very important point as the filters are probably very inaccurate now

 

[Juhazi]

Waste of time this article. Again.

To me this is thousand times more informative and interesting test than the thousanth dac or 2-way speaker test!

But where is the RIAA correction? https://en.wikipedia.org/wiki/RIAA_equalization

 

[Hiten]

This is a very important point as the filters are probably very inaccurate now

Probably input capacitor / resistor ?
Just curious though.
regards