Istari

I'd like to ask a couple of questions to the resident tube gurus. For starters I'm using a Fluke 23 digital multimeter (autosensing) and a generic variac to adjust line voltages , I also have a digital meter hooked up to the variac to acurately measure its output voltage. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /> I have a H.H. Scott 99A that Id like to rebuild. I have a bit of an electronics background but its somewhat rusty. I do have the schematics for the units (Sams Photofacts). One of my questions is this: On the 99A I have checked the voltage of V6 - 5Y3GT (output side of a new or original 5Y3GT, I tried both thinking that the old tube may have been defective) at pins 2 & 8 and it measures 396 V after a 10 minute warm up. The voltage measurement on the schematic reads 355 V. I have the 99A plugged into a variac that is set at 117 VAC, which the Photofact states in the nominal voltage. (The Photofact states: Nominal tolerances on component values makes possible a variance of + or 15% in voltage and resistance values.) The higher reading of 396 V throws off all of the other readings Im taking on tube V2 12AX7 (pin 1 actual 210.2 V, schematic 175 V; pin 6 actual 241.3 V, schematic 195 V and on tube V4 6V6GT (pin 3 actual 359 V, schematic 325 V; pin 4 actual 364, schematic 320 V. If I adjust the variac to 106 volts, I then get the correct reading from V6 pins 2 & 8 of 355 V and the other readings are very close to the schematic values. My question is, should I worry about the higher voltage readings since the schematic says that there could be a + or 15% in the readings of voltage and resistance? Should I insert a high wattage pot and reduce the output voltage on V6 pin 2 or 8? I have changed out the coupling caps but not any of the multisection cans. I have a 99C that is exhibiting similar increases on the 54UGA output and 12AX7 and 6L6GB tubes. I have replaced the 4X20 MF multisection electrolytic capacitor and I have replaced the coupling caps with orange drop equivalents. Would replacing the multisections have an effect on the voltage readings of the rectifier tubes? Both units power up and play well, I just want to be sure that the 99A can last another 53 years! I intend on using either the 99A or the C as center channel amps, the C model looks better with the Scott 222A I have, but the 99A is a real looker with its brass faceplate all polished up. The Scott 222A was rebuilt by Craig Otsby (NOS Valves) about two years ago and works well. Id just like to see if I can bring these back up to equal the 222A. I'll attempt to attach the 99A schematic to this post. Thanks for the help!

It would help if you put the serial numbers in...

Tigerwoods, I'd like to buy your HK 630! I've got the $75.00 plus whatever you need for shipping. I've been trying to get one of these off of EBay but have been outbid at the last minute. It the 630 still available? I've sent you a PM.

Since they are going to be in a colllege set up, I would fuse them. Buy enough of the inline fuse holders and put one each in the + (Red) lead going to the speaker. These are easy enough to put in the speaker wire. I'd start with a 1 amp fast blow fuse. You can get both items at a Radio Shack or at Parts Express. You'll be glad you did the first time a fuse blows and saves your speaker!!!! Be sure and buy extra fuses for replacements.[]

The 222 was rebuilt by NOSValves, I rebuilt the other two. The 99A was a challenge since it was built the year I was born (1953). You're not going to sell those Corns again are you???

Jon!, How are you bud?, are those old cornwalls holding up OK? I've got a soldering iron and a few resistors if you want to try your luck. I've restored a couple of tube amps, so i could give you a few pointers on soldering.

You may want double RCAs for the output. You use one for the center channel and one for a subwoofer. Thats how i have my PWK 3 channel set up.

Douglas, Are these up for sale? I'll take them at the 600 price and you can keep the risers! Please email me at: James.mcClung@mail.va.gov

"except in the noise canceling effect", Ah that's why you buy them..... They are noise cancelling.. I have a pair of the bose noise cancelling headsets and they work pretty well for their intended use. They do reduce the noise but not eliminate it. They are pricey and there are other units at 1/3 of the cost. If you are in a larger airport look for the Brookstone stores. They have a model that pretty nice.

So I guess that if the La Scala was built for a REPUBLICAN, the Belle was built for a DEMOCRAT? Sounds good to me.

Since you have an Odyssey be sure to take plenty of padding (blankets, rugs and so forth) to cover the floor of the van. Its a bit uneven and has all of the seat hardware on the floor.

Sorry for the double post!!!

Length should be no shorter than four feet, anything longer than four feet does not add to the effect.

Glad to see you back Andy (HDBR). Its been awhile.

Dr. Bill, I remember that one back in '72 great disc. I guess what sets it off is the Mo Tab singing the Russian Hymn, I haven't heard that on any other disc. I really think it tops the Telarc version. BTW, thanks again for the center channel box, it works great!, I'm currently driving a Belle as a center between Klipschorns.

I'd go for it! I was able to pick up a 99A and a 99C and rebuild both. The 99C is now pulling center channel duty driving a Belle. The 99A cleaned up like new and is a display piece for the short haul.

How much were they Tony?

Yup, I will be. I'm going up to a max of $151.99. I've been wanting one for a while now.

Hummmm, I remember a saying from somewhere in my distant past.. Once you go Black, you'll never go back.....

Doesn't the Scott tube amp have a center out that you can attach both the 99D and the sub to? That is how I have my Scott 222, Scott 99C and M&K sub connected. In this configuration, the main volume knob on the 222 controls all of the volume levels on all devices.

Craig, You already had a pair of La Scalas in the workroom!!! I'll take them off your hands on my way to Alpena if you would like!? Jim

Thebes, Where are you in the DC area? I currently reside in Martinsburg, WV and make the trip into the District quite frequently.

I'm with you R Cherry. You know, I think it would be different if W had a son out pounding the ground. But no, he would do what his daddy did, pull strings and get his son a safe job here in the states. There is justice in the system, but its spelled "Just Us" and it takes money and political power to use it, the first Bush proved that. I'll be thinking of the boys and girls who won't have a father this father's day due to this private war in Iraq. Now before people jump in my _hit, I'm an Army Vet, served 6 years, 5 months and 12 days, I have earned the right to complain, and I have also earned you your right to complain. But you cant _itch if you haven't been in a troops boots. Good night all!

er, Input Protection.... Output from the amp, input to the speaker. I wouldn't go over a 1 amp Fast Blow, I'd probably start at a 1/2 or 3/4 amp, it depends on what you listen to and how loud you listen to it.

I just sent Scott an Email my address, I'm going to rebuild it and hook it up to my Cornwalls. Thanks for the offer Scott!!!