HH Scott 200

oldman55

Well-Known Member
Hello all
Somewhat limited diyer here but this appears to be a simple amp. Looking for a "list" of caps/etc that should be replaced due to age. Topside in excellent condition (tubes, pots, cosmetics, etc)....sound....not so well.
Does someone sell kits for restoration? Small amp so cant put too much $ into it.
Anything stand out from photo? This was kit version.
Thanks
 

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All those white cylindrical caps gotta go, they're always bad. Electrolytics cans are a maybe, under chassis electrolytics gotta go too. Just change the white cylinders with generic brown dip type 630V film caps, and electrolytics with same value and same or higher voltage rating. If you do all that and it still sounds bad, then time to troubleshoot. Looks like a nice little amp, I wouldn't imagine more than $30 in parts to change those caps.
 
All those white cylindrical caps gotta go, they're always bad. Electrolytics cans are a maybe, under chassis electrolytics gotta go too. Just change the white cylinders with generic brown dip type 630V film caps, and electrolytics with same value and same or higher voltage rating. If you do all that and it still sounds bad, then time to troubleshoot. Looks like a nice little amp, I wouldn't imagine more than $30 in parts to change those caps.

Aren't all those caps cylindrical? Where are the electolytics?

Remember that I described my skills as "limitied" :)
 

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Aren't all those caps cylindrical? Where are the electolytics?

Remember that I described my skills as "limitied" :)

The white ones with the black stripe on one end are probably paper, they're usually leaky at this age. The black one up in the upper left corner with a + on one end is an electrolytic. I strongly suggest getting a service manual, it will help identify all the parts. Very nice little amp

The "cans" are the capacitors on top of the chassis, vertical aluminum cylinders
 
Howard w sams made service manuals for all things electronics, kind of like Haynes manuals are to cars. You can download them from their website for about $15. If you value your time I strongly suggest getting one, I usually download the sams when I am fixing something unfamiliar, it's super useful
 
I should be a little more specific - the sams manuals usually have a full schematic, parts list, photos showing with arrows where all the parts are, and disassembly instructions. More or less all the info you need to fix it, especiall when this stuff is new to you and you dont know what's what yet
 
I'm listening to a Scott 200 right now, and I have to say, I love it. I didn't think it would be as good as other Scotts but it is, I was gonna sell this one, but it really is sounding too good!
All power supply caps replaced, all coupling caps are west-cap pio, K40y pio or astron pio, mepco gold plate resistors, just sounds great.
 

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I should be a little more specific - the sams manuals usually have a full schematic, parts list, photos showing with arrows where all the parts are, and disassembly instructions. More or less all the info you need to fix it, especiall when this stuff is new to you and you dont know what's what yet
Can only find schematic and users manual online. Don't know if Sams covered this unit. Anyone have a link?
 
You should do fine with just the schematic. Yes, Sams had pictures of the layout. But the 200/LK30/200B was a very basic amplifier made by Scott. I have a couple of them and they do perform well. Not gobs of power but great for a small room or efficient speakers. But most important, they are vacuum tube amplifiers 100%!
 
I just checked the Howard W. Sams database. They do not seem to have the H. H. Scott 200 or 200B.
 
If there's no sams, I agree that the schematic will suffice - sams is a nice to have though when there is one.
 
That is an actual HH Scott schematic. They came with the equipment. If you look in the lower right-hand corner, you can see the engineering information. Some of the schematics on the HH Scott site are Sams. But the one in your link is an original. BTW, Scott did not have a legend. What was on the print was all that you got.
 
That's a nice clear schematic that gives you all you need to know, including relevant voltages. If you aren't confident about reading the schematic, just ask here. The caps which have polarity marked will be electrolytics. Replacement caps should be the nearest value and the same or higher voltage rating. Replace like for like.

I just thought, maybe you could ask Brycecb750 to send you some high res pics of his amp. That will show you the caps that he replaced.
 
That's a nice clear schematic that gives you all you need to know, including relevant voltages. If you aren't confident about reading the schematic, just ask here. The caps which have polarity marked will be electrolytics. Replacement caps should be the nearest value and the same or higher voltage rating. Replace like for like.

I just thought, maybe you could ask Brycecb750 to send you some high res pics of his amp. That will show you the caps that he replaced.

Pics would be great. Was hesitant about which all I could replace with dip type. Dont see voltage ratings on schematic and alot of caps have the print unreadable. It does appear to me that Scott labeled them with their part number?
 
Many of the American Radionic Ceracap capacitors are 400 WVDC. You can and should replace them with the modern voltage, 630 WVDC. I use the yellow axial capacitors for Scott amplifiers. I have used "Orange Drops" in the past but they can be difficult since they are radial leads instead of axial leads which lends itself better to point-to-point wiring as in a Scott amplifier. Below is a .1μFD, 400 WVDC Ceracap in a Scott amplifier.

CERACAP_zps8c861c7e.jpg


I know others have different opinions about which capacitor to use. I will only tell you what I use and I am totally satisfied with the results. Just as a disclaimer, I am not into boutique capacitors or any of that stuff. One is totally free to use whatever one wants to use.

This is my first edition 299. You can see how the radial lead Orange Drops are somewhat difficult to place in those small spaces.

299-Bottom.jpg


And this is what it looks like with yellow axial capacitors:

Bottom_zpsvbwemesn.jpg
 
I agree with the above posts, if you just use 630V for all of the film capacitors, 450V for the electrolytic filters, and say 160V for the bias filter, you won't go wrong. No harm in going a bit high on voltage ratings.
 
Be careful with your filter capacitors. Many if not most of what Scott used was 500 WVDC electrolytic capacitors because the voltage can surge high until the output stage starts conducting. With the 340/345/380 tube receivers, the power supply is silicon rectifiers and that B+ will be immediate.

I know that it is difficult to find 500 WVDC electrolytic capacitors and 600 WVDC are even more difficult. The same issue exists with Dynaco amplifiers.

Not to be a hypocrite, I have used 450 or 475 WVDC electrolytics when 500 WVDC capacitors were not available or if I wanted to get done.
 
Be careful with your filter capacitors. Many if not most of what Scott used was 500 WVDC electrolytic capacitors because the voltage can surge high until the output stage starts conducting. With the 340/345/380 tube receivers, the power supply is silicon rectifiers and that B+ will be immediate.

I know that it is difficult to find 500 WVDC electrolytic capacitors and 600 WVDC are even more difficult. The same issue exists with Dynaco amplifiers.

Not to be a hypocrite, I have used 450 or 475 WVDC electrolytics when 500 WVDC capacitors were not available or if I wanted to get done.

This thing has a GZ34, which should warm up slower than the output tubes, plus those ECL86 tubes (or whatever they are) can't take very high voltage to begin with. Schematic says B+ is 300V and filters are rated at 400V. I still think it's worth verifying though that 450 is adequate, but I would bet money that in this case it will be.
 
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