Jimbo Bob

This might interest you. http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/ammet.html#c1 I'd be really surprised that even on your non-switchable ammeter there wouldn't be any shunting resistor (would it be only for protection purpose). Anyway... Have fun with your quest for the most accurate way way to bias a Scott.

Dear Expert, Even your magical non-switcheable ammeter have a resistance, would it be in the coil of the d'Arsonval meter itself. The fact that you don't see this is "food for thoughts" to say the least. The multimeters of today render useless your method from "back then". Measuring the voltage drop will be as much accurate. Why can't you see it!!! Sometimes reading your posts I feel like you have some knowledge but when you come up with ridiculous stuff like your biasing accuracy measurement I really wonder what cross your mind.

---------------- Correct, if you know the actual resistance of *each* resistor, you can then use Ohm's Law to determine the voltage drop. Using vintage meters with a lower input impedance will yield decent results, using a modern meter with a much higher input impedance will yield more accurate results. This discussion was about which method is the most accurate, measuring cathode (as per Scott spec) or calculating voltage drop. Either method will work, but most technicians back then wouldn't go through the trouble of measuring the actual resistance of the resistors, therefore, the cathode current method was a better choice, since the resistance had no affect on the current reading. The correct meter (non-switchable milliammeter) is not expensive, and can be purchased for $20 or less from any major distributor, and will produce the most accurate bias adjustments. Voltmeters do have a tolerance range, and whatever the tolerance may be, that will also be the tolerance of your bias adjustment, plus the resistor tolerance. The non-switchable milliammeter has a tolerance rating of 1/10 of a percent (that's close enough for me). The tolerance rating of your voltmeter can be found in the owners manual for the meter. The tolerance rating of the resistors can be viewed by directly looking at the resistors. A silver band means 10% tolerance, gold band means 5% tolerance. Best Regards, Ryan ---------------- Dear Mr. Expert! You are surely the king when it comes to running around in circle. Read again Mdeneen's posts please and try to think for yourself instead of pulling out again this "H H Scott said..." over and over again. An engineer like you is suppose to think, not to worship.

Geez this was funny!!! The two resident Scott experts here are no engineers. Entertaining they are for sure. But I'll give Craig the real will to learn as opiniated he may be!

"Comments?" Yes. Since you claim to be an engineer, you should never take anything for granted, be the source H.H. Scott or even God himself! So do this little experiment. Take your measurements with your "current across the resistor method", by measuring the current after breaking open the circuit and by measuring the voltage drop across the 10 ohm resistor and by applying Ohm's law with the actual resistor value and report back on the 3 current values measured/infered. While at the same time, try to be humble enough to learn how a ammeter works. Go back to the EXCELLENT post by Mark. Check his suggested reading it might help you a bit.

It's the Funk Brothers.

At that price I really think it's a no brainer. The 6DJ8 is a good tube to use in a phono preamp. The Bottlehead kits have always been really good value for the money and the support you'll have either by Doc B or the member of his forum is just incredible.

Chris As a Led Zep fan, I bought How the West was Won the day it came out. I now wish I wouldn't have. Unless you're looking for, yet another, endless version of Dazed and Confused and some 15 to 20 minutes versions of their classics, you can skip this set. Musical performance is at best "not bad". Most guitaristic exploits are piss poor AND loooooooong. Unless for you rock'n roll ended in the 70s, I'd spend my money elsewhere. Sonically, it screams "Eddy Kramer taped this". I really felt I was listening to Kiss Alive I or II (souvenirs). For extreme case of mid-life crisis only (or die hard Led Zep fans)

Sorry Craig! Your "inspired" answer made you step back from "half blind" status to "blind" status.

This thread was entertaining! Maybe our two Scott self proclaimed resident experts could benefit by reading the following links. It would certainly contribute to clear some slight misunderstanding they seem to have about phase splitting devices. Sorry for the "gibberish tech talk" involved in these thread but you either understand this stuff or you don't. Simple stuff first: http://www.bonavolta.ch/hobby/en/audio/split.htm#Cathodyne Pro cathodyne camp should rejoyce with this: http://www.aikenamps.com/cathodyne.pdf Lots of interesting stuff here: http://www.aikenamps.com/TI_Other.htm Now from a tube iconoclast I enjoy: http://members.fortunecity.com/ultrafi/splitter.html In the Kingdom of the blinds the half blind is king?.... Nahhhh.... Enjoy the read guys!