Sherwood build quality is not as impressive as Marantz, but manages a significant sonic mojo. The receivers sound bigger than their advertised wattage and the tuners are solid all 'round performers. Cosmetically, Sherwood lags a bit behind Marantz, but a clean example represents '70s hifi style very well.
The 7310 offers the David Hafler's Dynaquad circuitry, an island of sanity in this era of quad madness:
This 7310 worked well on arrival. Even the lamps worked. So, on with the restoration! The board layout is straight forward with only the treble/bass board presenting a significant challenge. Here is the bird's eye view from the top:
The power supply board is at the lower right, below the transformer. The output boards are in the upper middle and are accessible from below. The tuning capacitor is at the upper left, shielded. Immediately below it are the AM and FM boards that required removal of 4 screws and some tugging to restore. But whither phono?
The phono board is located underneath the unit, at the upper left in this photo. Note the two power supply filter caps in the upper right corner. These slightly obscure the treble/bass board that hides just behind the face of the unit. Changing the caps on this board requires peeling the face and unclamping the filter caps. As luck would have it, my back order of Elna Silmic II caps had just arrived so the 8 4.7 mfd caps on this small board were replaced with silk. The tone control circuit is not defeatable, so it better sound sweet when driven by the cd player not yet imagined in 1975.All other caps were replaced with Panasonic FCs with extra margin on the voltages. A total of 50 caps were replaced, the 6.8k main filters were left as is. Pots and switches were cleaned with Blue Foam and Deoxit Gold. The tuning capacitor was spritzed with Deoxit Gold.
The end result of my labors was a very sweet sounding unit that should last for another 20-30 years. The overall sound is lush for a string quartet with enough punch to do justice to Metallica. And it looks good. One more look with a bit of drama:
12 comments:
Well , I was given two of these Sherwood amplifiers. The S7310 and an S7310A. Both seem to work, on the S7310A I noticed it does not have an power off. I turn the Loudness knob counter clockwise and it will not power off , no click .. Strange.
But since I use the one for my computer hookup, get all sound from the computer coming threw the stereo out to the speakers. Recently Received a Squire Fender, with out a guitar amp. I plugged in the guitar to the tape dubbing port, and works just fine as a temporary guitar amp. I am of course not turning the volume up past half way so , I think the possibility of burning up the amp is very small. Already have a plan for a guitar amp FENDER Bullet 15 DSP from the local pawn shop.
But all and all I am thoroughly impressed with the quality of this amp. As it is getting on in years when Powering on and off sometimes get some funny noises , crackles , pops. Also sometimes the right stereo channel will go out from time to time, but will usually come back if I cycle between the entire array of settings, AUX1, AUX2, AM, FM, Phono then back again it will come back. It has been suggested to me that If I wish to try and save this retro amp, I may want to take some contact cleaner to the inside. I am professional enough to work with the electronics inside, but until there is a catastrophic problem I think I will leave well enough alone.
Thanks for listening.
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Help, please. All recommend this program to effectively advertise on the Internet, this is the best program!
I just encountered the same problem with the loudness knob on my Sherwood (no click off). Did you find a fix?
No , I have not found a solution or cute to this problem. Basically leave the unit on 24 hours a day turned all the way down, sometimes I will shut everything down for a while.. But that is at the power strip. Im not sure I think it has something to do with a cam that is on the inside of the shaft, dealing with the power off switch.. When the cam is turned to the off position it moves the on off button.. Only thing I can think of. Get a power strip, and just power it off at the wall. Because your not going to have too much luck in finding replacement parts for the unit.
I used to work for Sherwood in the early seventies and at that time purchased an S-7310. The on off function was included as part of the loudness/volume control. This switch like others have experienced failed. Not a reliable design. Not able to find a suitable replacement, I was able to drill an hole next to the balance control where I was able to install an on/off toggle switch. It's a tight spot but workable. Well worth the effort for a receiver that's worth keeping operational.
In the early 70's, I purchased a new Sherwood S-7100A and a pair of Smaller Advent Loudspeakers then added a used Dual 1215S with a Shure M91ED cartridge. After a few years, sometime in the late 80's, the right channel stopped working, but a friend was able to diagnose and fix it. Another decade passed, and I had the power switch failure. I removed the faceplate and saw that a piece of breadboard-like material had snapped and would not break the power connection, so I drilled a hole beside the loudness knob and added a locking lighted pushbutton from Radio Shack and tapped into the power circuit which fixed the problem. (I also had to have the Smaller Advent woofer's re-foamed and they are still singing today). Even though the S-7100A is still working fine, I got the itch to upgrade to the S-7310 that I originally wanted but could not afford when I got out of the Air Force so when I found one on eBay for a pittance, I bought it. It has been working fine for 4 years or so, but last year had the same power switch failure. I don't know if I will take the time to re-vamp it like I did the S-7100A, but I actually may have a spare locking lighted switch, so that might be something I will tackle.
Hi, I bought the 7310 and working on recapping it; however, could not find the service manual on the net. Do you have the manual?
I just picked up a 7310 in great shape; after a cleaning of all the pots and switches it sounds like new. Recapping is in the future, as is sussing out a cure for the Sherwood power switch curse. As others have noted, many of these won't switch off and it's because of a cheap plastic piece that snapped off in (I'm told) 75% or more of the units over time. A guy on Audiokarma claims a fix (google Sherwood receiver power switch and you'll probably see the thread) and there's a guy on eBay selling new switch/volume control gangs for the princely sum of $90. Or you can add a separate switch as others have done.
Great receiver; it was my first higher end unit in the mid '70s and I'm happy to have one back. It's driving a set of ESS Performance 5's and sounds amazing.
Thinking of replacing the two large capacitors in my Sherwood 7310A.. Every time I turn the unit off from the power strip there is a large 'THUNK!' sound coming from the speakers.. So Pulled it apart. Two Nippon Chemi-Con 8000 uF 50 V capacitors.. Not sure if they are in series or parallel. Also had the cute idea of instead of getting two capacitors I could just get one at 160000 uF but I think the unit needs both capacitors to smooth out the ripple. Checked out some stuff on Mouser and can get the capacitors off of that site.. Only $4.00 each plus shipping.. Kinda like the design, very basic , everything on small boards.. Easy to get at .. Will let everyone know how things work out.. and perhaps I will pull the volume knob and see if I can pull a rabbit out of a hat so to speak and make it work again.
This is an old string, but just found it.
I had a 7210 for decades, and the power off on the volume know went off. I went to Radio Shack and bought a toggle switch. I pulled out the tape dubbing jack and inserted the switch in the power path. Worked great, with only drawback being without a relay in the line you get the THUMP when flipping the switch off.
G
I have three Sherwoods heading to me from eBay purchases. I'm no tech, but have ruined my eyesight reading all I can find online related to these lower wattage Sherwoods. It seems Deoxit D5 cleaner actually ruins the plastic innards of the combo volume/power switch. Supposed to user Deoxit Fader cleaner to avoid this issue. But I'm sure simple old age is the cause of failure in many cases.
My first Sherwood is an S-5000 tube amp. I've had it recapped and serviced.
I definitely like these great quality, great sounding...but much CHEAPER less popular brand names. Sherwoods, Rotels, and Soundcraftsmen. Usually costing $75 - $200 depending on condition and wattage.
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