H. H. Scott and Fisher

[SDS-PAGE]

The one that I bought seems to be silver faced, at least that's how it appears on the pictures. At any rate, I will have to check the can caps for leakage. I was going to replace signal caps too.

[erichayes]

Gold faced Scotts had gold knobs; silver faced had, IIRC, brown knobs with a metallic circumference bead, or a silver escutcheon on the fronts (a la Marshall amps).

The circuitry didn't change significantly between the two generations. The main thing to look for is a very shallow chassis pan made of fairly thick aluminum. That was the cause of the cap failures. There wasn't enough "air room" underneath the chassis for the components to dissipate the heat, and the chassis being made of Al only exacerbated the deterioration due to heat conduction from the chassis up into the cans.

I want to reiterate that the cans are toast and can't be rejuvenated. The coupling caps are probably leaky, and need to be replaced, as well.

As always, Min, feel free to give me a call if you have questions.

[crispycircuit]

SDS- Congradulations! You got yourself a beauty. Your unit also has the very desirable bias adj & bal pots and bias test point. Most do NOT have this. I use the JJ quad or dual section can caps. But the low voltage quad cap you can fit the caps underneath. Or take an old can cap drill out all the old guts (stinky) and put new caps in with silicone glue. (I only do it on my own units). It is time consuming and check for drifted resistors. Scott really went the distance to make one the best integeteds to be compared to anything out there. NICE STUFF. I own a LK72 and enjoy the hell out of it...

[SDS-PAGE]

I got my Scott today. The unit looks surprisingly clean. No rust anywhere on the chassis. Nothing but shiny metal everywhere. Unfortunately, there is a slight depression where PT is around the rectifier. Nothing big. Must have happened when UPS guys were using the box as a stepping stool. Yellow_Light_Colorz_PDT_21

I fired it up and one channel goes dead intermittently. Apparently, one of 6U8As was bad - it stays heated most of the time, but occasionally goes weak. I confirm this on my tube tester. Gotta get a new set.

As it is, the amp sounds very impressive. This is one heck of an amp! I do like the tone control on it too.

BTW, I might like to replace the output tubes sometime. Anyone could recommend a good quad of EL-84s to use in a Scott? I have used a quad of JJs on a DIYTUBE ST-35 before. They sounded horrible breaking in, but ended up sounding good after a couple of months. Thanks!

[Ty_Bower]

I still really like the old Reflektor 6П14П-ЕВ, although it seems every time I look the eBay prices go up again. Eight years ago, I used to be able to get them for $2 each. Last year I grabbed a lot of 20 for $80 shipped. Now they're over $6.50 each. Hopefully, I've got enough stockpiled to last me...

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0242361347

[crispycircuit]

Congradulations! Your unit is one of the best Scott made. Your 6U8 driver tube. Sometimes Scott used a low value resistor in series with the heaters. The 6U8s are run off the AC heaters of the power tubes and this resistor doesn't hold up, just replace them. But it could be part of the problem.... Also make sure to replace the DC supply bridge. They drop to much voltage from age. A new one will bring up the heaters and bias to where it should be.... This is one amp you'll always enjoy..... Cheers!

[dcriner]

I re-did a Scott 222D. Sounds fine.

Let me modify my previous statement. I've never been impressed with the phono pre-amp section. Doesn't sound all that good to me. But the rest of the amp is fine.

[SDS-PAGE]

Output tube screen resistors should be checked for correct value if the output tubes aren't original (or even if they are, for that matter; original 299C output tubes were Telefunken 7189s, BTW).

So, this got me to take a closer look at my output tubes again. Almost all of the logos on all the tubes are gone, except for what appears to be the top corner of a concentric white diamond and clear "MADE IN WEST GERMANY" markings in all of them. Could these be Telefunkens? Maybe I'm wishing they were. Whatever they are they sound real good. Yellow_Light_Colorz_PDT_11

[TerrySmith]

Telefunken's have the diamond molded in the base, look inside the pin circle from the bottom.

That's a nice amp, will last another 40+ years. It's funny how the top brands like Scott, Fisher etc did not include a case, it was extra cost.

[SDS-PAGE]

I looked at the pin circle on the base. There are diamonds with numbers on each: two tubes have 19 and 6, other two have 18 and 6, and 26 and 6 engraved on them.

[Ty_Bower]

Too bad you don't have boxes for them...

http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... 0212501260

[sorenj07]

JJ or EH need to get their hands on a few of those real Telefunken 7189's and start cranking out clones. There is definitely a market.

[SDS-PAGE]

I just checked 12AX7s on my Scott. They are all Telefunkens with clear markings on all of them. I can't believe my luck. I got near mint Scott LK-48B with Telefunken output and preamp tubes (sans 6U8s) for 300 bucks. I wonder how much one of us would have sold it for?

P.S. Sorry if I sound like I am braggin'. I am just stoked about scoring something really cool unexpectedly.

[TerrySmith]

6U8/6GH8 family is an American type usually found in TV's.

I dug up a schematic on the interweb and noticed this amp uses fixed bias. This will make the output tubes run cooler and last longer.

[Ty_Bower]

I am just stoked about scoring something really cool unexpectedly.

It is exciting. I bought a pair of Mk3 blocks off Craigslist last summer. At first I was bummed when I brought them home and realized they weren't in as good condition as I thought. The can caps were cooked, the driver boards were nasty, and the chassis suddenly looked more pitted than they did when I went to pick them up.

Then I realized the KT88 were original Genalex and the rectifiers were original Mullard. The glass alone was easily worth more than what I paid. Funny thing is, I didn't know it at the time I picked it up. Sometimes you get lucky...