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Sherwood S-7100A Illumination

MCM_Fan

MCM_Fan

AK Subscriber
While I had my Sherwood S-7100A opened up for some other maintenance, I thought I'd look into why the illumination of the scale looks so dull and lifeless. Here's what I found:

Sherwood_S-7100_A_Illumination.jpg


Sherwood_S-7100_A_Illumination_2.jpg


As you can see, there is quite a bit of carbon build up inside the fuse lamps. Not a big deal. They are standard 8V, 0.3A fuse lamps. I think I may even have a couple on hand. That would explain the lack of brightness compared to other vintage receivers I have re-lamped.

The second issue is the blue plastic filters that fit between the lamps and the ends of the dial scale have completely burned through over time.

I actually don't think these blue filters were designed to create blue illumination. I think they were originally intended to remove the strong yellow cast of the incandescent fuse bulbs. Yellow and blue are complementary colors and in photography a strong blue filter (Wratten 80A) is often used over a lens to correct for proper white balance when shooting under incandescent illumination.

It looks like I have some choices. The obvious choice would be to replace the original lamps with some new 8V .3A incandescent fuse lamps, but that would also require replacing the damaged blue filter pieces. Can anyone recommend a source for replacements? Maybe get a Wratten 80A filter and make my own.

The other option is to replace the original incandescent fuse lamps with some LED lamps. These come in warm white, blue and even turquoise. I've seen photos using blue LEDs, and I don't think that's what I want. They look too blue, and as I said above, I don't think the original blue filters were intended to create a blue light, just to cancel out the strong yellow cast of the incandescent lamps.

Turquoise LEDs are interesting, because as you can see i the second photo, the original scale has a turquoise color. Has anyone tried Turquoise LEDs in a vintage receiver? If so, how did you like the results (please feel free to share a photo or two).

The final option would be the warm white LED lamps with no blue filter. Has anyone tried this? Again, photos and opinions are welcome.
 
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If you want to go with LED's might I suggest you use a cool or neutral white. If you wish to go with incandescents I suppose you could rotate the original blue filters so that the damaged part isn't aiming at the scale or maybe some blue transparent vinyl wrap?
 
Eastham said:
If you want to go with LED's might I suggest you use a cool or neutral white. If you wish to go with incandescents I suppose you could rotate the original blue filters so that the damaged part isn't aiming at the scale or maybe some blue transparent vinyl wrap?
Click to expand...

Thanks for the suggestions. I'm not sure if you can tell from the photos, but the blue filters are bent and a 90-degree angle and the two sides are asymmetrical. They are quite brittle, especially around the area that burnt through. I have some incandescent lamps on hand (7V, 0.3A instead of the original 8V, 0.3A) so I may as well give it a try. I have a heat gun. Maybe I'll warn up the plastic a little before I try to re-bend them.
 
MCM_Fan said:
Thanks for the suggestions. I'm not sure if you can tell from the photos, but the blue filters are bent and a 90-degree angle and the two sides are asymmetrical. They are quite brittle, especially around the area that burnt through. I have some incandescent lamps on hand (7V, 0.3A instead of the original 8V, 0.3A) so I may as well give it a try. I have a heat gun. Maybe I'll warn up the plastic a little before I try to re-bend them.
Click to expand...

No harm in trying.
 
That worked reasonably well. Replacing the old lamps brightened things up and flipping the blue filters give the scale a nice baby blue color. Rather than try to re-bend, and risk breaking, the thin plastic blue filters, I simply trimmed the long side to be the same width as the shirt side.

I'm listening to Fleetwood Mac - The Dance right now through a pair of Electro-Voice Interface D speakers and it sounds great.

I'll try to get a photo, or two, posted tomorrow.
 
redk9258 said:
Those 7V bulbs will run hotter than 8V. They will likely die an early death. Get the proper ones!
This is probably the correct one. Check the data sheet....

http://www.mouser.com/ProductDetail/JKL-Components/GF680
Click to expand...

Understood. I just happened to have a bunch of the 7V 0.3A fuse lamps on hand. I bought a lot of 24 of them on eBay about 4 or 5 years ago. By buying in bulk, I got them for less than a buck each, including free shipping. I'll order some of the 8V lamps and swap them in for the 7V lamps when they get here.
 
MCM_Fan,
I put warm white LEDs in mine.
The blue films were nearly completely burnt up, and I have not replaced them.
I get a light green color on the dial numbers, as you might guess from the blue numbering and the yellowish output of the lamps.
Your tuning meter is close to the color I see on the dial.
My camera is hosed at the moment, so I cannot post a picture. Sorry.

It looks pretty good actually, but it is not original.
After seeing yours I may improvise replacements one day soon.

You did a great job with the photos.
It's difficult to accurately capture the lit dial and expose the rest of the unit properly.
Your pics show really that the S7100-A is a cut above other 15 W/ch receivers of its time in build quality.

I can't fault the sound quality of mine either.
It's a wonderful receiver that gets far less attention than it deserves.
 
rkgren1 said:
MCM_Fan,
I put warm white LEDs in mine.
The blue films were nearly completely burnt up, and I have not replaced them.
I get a light green color on the dial numbers, as you might guess from the blue numbering and the yellowish output of the lamps.
Your tuning meter is close to the color I see on the dial.
My camera is hosed at the moment, so I cannot post a picture. Sorry.

It looks pretty good actually, but it is not original.
After seeing yours I may improvise replacements one day soon.

You did a great job with the photos.
It's difficult to accurately capture the lit dial and expose the rest of the unit properly.
Your pics show really that the S7100-A is a cut above other 15 W/ch receivers of its time in build quality.

I can't fault the sound quality of mine either.
It's a wonderful receiver that gets far less attention than it deserves.
Click to expand...

Thanks for the feedback. I love looking at photos of audio gear almost as much as I love looking at the gear. I just think some of the vintage gear, even something as humble as this little Sherwood S-7100A, is just absolutely beautiful. So, I always try to do it justice when posting photos of my gear.

My girlfriend and I both have agreed this one is a keeper - both for the looks and the sound quality. I think one of the benefits of it being a low power receiver is no vents on the top of the case needed for cooling. I just love the looks of that walnut veneer case. Throw in the baby blue tuning dial and it has a subtle, understated look that I find elegant beautiful.

I just need to find a replacement knob for the one that's missing.

Those who have heard the S-7100A praise it for it's sound quality. I'm also pleasantly surprised how good the tuner sounds. I've been listening to it quite a bit the last few days, and it really sounds great. I currently have it hooked up to a 3-piece 3D Acoustics 3D610B speaker system and the imaging is amazing. Hard to believe such a humble little system can sound this good!

3_D_Acoustics_3_D610_B_1.jpg
 
Sherwood Pic

Sherwood Pic

  • Media owner yamaha53
  • Date added

Here is my 7100A that is in my wife's dressing room. Love the look of this unit. I am guessing that these are the original lights. Seems to be a low hour unit ( notice the discs behind the volume and tuning knobs). The phone stage on this receiver is one of the best I have heard. Very warm and cozy. If I ever tape an album I use this one. But I have noticed that when I see a picture of these receivers, I am the only one running the loudness ON. Does it color the sound too much for most ears this way?
 
yamaha53 said:
But I have noticed that when I see a picture of these receivers, I am the only one running the loudness ON. Does it color the sound too much for most ears this way?
Click to expand...

I think it depends on several variables: your speakers, your room environment, your average listening level and probably most of all personal preference. I've only tried my S-7100A with two different speaker systems so far (Electro-Voice Interface D and 3D Acoustics 3D610B) and in both cases, I found I preferred the sound with the loudness contour turned off.

In addition to personal preference and speaker types, I think my room environment/speaker placement and average listening level played a part in my decision. Both the the speakers systems I tried have downward firing woofers and neither lack bass, especially the Interface D, which have their own dedicated equalizer that insure flat frequency response down to 28Hz and -2.5dB at 18HZ. In both cases, with these two speaker systems, in my listening environment, I found engaging the loudness contour added too much bass and gave the bass a boomy quality I didn't like, especially at moderate listening levels.

Again, I've only tested the S-7100A with these two speaker systems, but it does seem to be more aggressive than the loudness contour of other vintage receivers and integrated amps I've owned - especially at moderate listening levels. My opinion might change if I was running a pair of small, bass shy, stand mounted bookshelf speakers. In that case, the loudness contour may help compensate for the lack of bass of the smaller speakers.
 
For me more than anything it depended on the speakers.I do use it on for headphones(early 90s Sony mdrv6) IIRC.I have a nice example but has been out of rotation for a bit.
 
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yamaha53 said:
Sherwood Pic

Sherwood Pic

  • Media owner yamaha53
  • Date added

Here is my 7100A that is in my wife's dressing room. Love the look of this unit. I am guessing that these are the original lights. Seems to be a low hour unit ( notice the discs behind the volume and tuning knobs). The phone stage on this receiver is one of the best I have heard. Very warm and cozy. If I ever tape an album I use this one. But I have noticed that when I see a picture of these receivers, I am the only one running the loudness ON. Does it color the sound too much for most ears this way?
Click to expand...

My S7100-A is plenty strong with the tone controls flat. With the loudness on and my present speakers I find it too biased toward the low frequencies.
Reading posts about this receiver on this site indicates that these receivers are very warm in tone on average, which makes them particularly nice for listening at modest volume levels. No loudness needed.
 
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