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I'm trying a out a pair of GE 6L6 GC that's gone through a fair amount of braking in from a different amp. It seems like the sonic is getting better in my amp the more I use it. Is it possible that my amp or the tube is readjusting itself to be in line with each other or am I imagining things.
Since my amp is rated 8watts/ch with KT88s, how many watts am I getting with the 6L6GC. The amp has a SE configuration.
Thanks
Follow Ups:
I see you have a Quicksilver SET. The "T" in SET means triode so I assume the KT88 is triode wired.
someone is going to have to school me how in the world you can get 8 watts from one triode wired KT88. 4 maybe but 8, no.
this is such a weird hobby. Facts don't seem to count for nothing.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Isn't this about the same? Designer is Dennis Had..Inspire Universal Firebottle SET Tube Amp. He uses the same tube and claims the same amount of power.
I don't care who the designer is. The facts don't care who the designer is.
If it's a KT88 wired in triode mode it will not give you 8 watts. Period.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
not without some grid current...:)
cheers,
Douglas
Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.
Yeah, that would help but the ad print doesn't say anything about a IT. Can a triode wired KT88 be properly driven by a 6H30 into A2 without an IT?
" QUICKSILVER SET MONO AMP
The Quicksilver single-ended amplifier uses no global feedback and yet offers lower distortion, wider frequency response and higher damping than standard single-ended designs. The parts list includes polypropylene and foil capacitors, non-inductive wirewound resistors, audio-core chokes and Quicksilver-designed power and output transformers.
As with all Quicksilver amplifiers, many different output tubes may be used. The power bandwidth extends to 20Hz and the 9 watts output has less than 1db of compression. Each output transformer is individually tested and categorized so that each pair of amps will have closely matched output characteristics. The amplifiers are finished in carbide black with nickel chrome transformer covers. The following specifications are provided for reference only. Sound quality performance can only be evaluated by direct comparison in your system.
Quicksilver SET Mono Amplifier Specifications
- Power output: 9 watts into 4 or 8 ohms
- Power bandwidth: 20Hz - 80kHz
- One-watt frequency response: 5Hz - 100kHz
- Damping factor: 8
- Hum and Noise: 90dB below 9 watts
- One-watt IM distortion: simple order 0.3%
- Global feedback: None
- Input sensitivity: 1.7 volts
- Input impedance: 300k ohms
- Power consumption: 140 watts
- Tube complement: 1-6H30 driver and input, 1-5AR4 rectifier, and 1-KT88 output tube
- Finish: Black chassis with chrome transformer covers
- Dimensions: 7"h x 14.5"d x 9.125"w
- Weight: 36 lbs., 39 lbs. shipping weight
- Warranty: 3 years parts and labor, tubes 90 days
"
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
So its name says 'SET'. And uses no global NFB. Its damping factor is 8, which suggests an output Z of 1R including the DCR of the OPT secondary.
9W is in between what you'd get in A1 triode, and what's available with UL and pentode. I have no trouble believing that they are taking descriptive liberties with their ad copy. It is just a matter of what exactly they are up to...LOL
cheers,
Douglas
Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.
"I have no trouble believing that they are taking descriptive liberties with their ad copy."
That makes two of us.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
I can envision a circuit that would do well I think. A cascade of the 6H30 sections; first running open-loop, and the second getting plate-to-cathode FB from the final. Picture half( or one phase-worth) the RCA SP10 circuit, but swap the 6AU6 for a section of the 6H30 and adjust the resistor networks to deal with a proper OP and FB level.
I suspect it will sound pretty fine, especially given the SP10's performance. Best sounding off-the-rack amp I have heard so far.
cheers,
Douglas
Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.
Maybe, not sure but that may make sense
Yup, that would make sense but the ad print says "The Quicksilver single-ended amplifier uses no global feedback and yet offers lower distortion, wider frequency response and higher damping than standard single-ended designs."I don't know how one can honestly claim "lower distortion than standard single-ended designs" if there is no feedback and the tube is wired in tetrode?
The key word here is "honestly". There is just so much BS in this hobby.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Edits: 04/13/20
Ok, so possibly the 'no global FB' is a clue. Recall the numbers published by Pete Millett on his E-Linear KT88 amp. Definitely not a triode( though with the E-Linear FB the AC plate curves sure will look like a triode ).
And you're right, Hi-Fi dealers tend to lie like drump.
cheers,
Douglas
Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.
A circuit optimized (designed) for a KT-88 will not be a great match for a 6L6GC
The B+ for the KT-88 will eat the 6L6GC up, and the impedance match for the OPT will not be great-
Tube swapping can be done - within limits -
There was a great conversation about the Octal Power Tubes back in the early '90s between Rodger Modjeski and David Manley about the interoperability of the tubes- and while 6550s and KT-88s are ok to swap and only adjust the bias (for amps designed to, EL-34, 6CA7, KT-77 need a deeper range on the bias - and ideally a bit less on the B+ (if the B+ is at the top of the range for the KT-88/6550)
Going to the KT-66/6L6GC, the B+ needs to come down even further and the bias then shifts-
Long Live the Nimble Tube Rollers Society !
(do you still have your button?)
Happy Listening
The amp is a pair of Quicksilver SET. I emailed Mike Sanders to ask if it's okay to swap them. He said no problem at all. I just pulled the KT88s and I'm currently using a pair of NOS GEC KT66 with amazing results. I think some of his amps have interchangeable tubes.
http://quicksilveraudio.com/products/midi-mono/
No more, probably less power. A 6L6GC in an amp designed for KT88 is going to have a short life span.
Dan Santoni
Plate dissipation is lower on the 6L6gc and the plate impedance is higher than the KT88. If your circuit is optimized for a KT88 and this depends on lots of things such as B+ voltage and output transformer impedance, you are probably losing about 30 to 40% of your power if I had to guess.If you have a scope and a signal generator, you can take a general measurement and get an idea what the power is but you won't know at what distortion level but you can at least see where the sinewave flattens out.
"For every complex problem there is an answer that is clear, simple, and wrong" H. L. Mencken
There have been discussions about this from time to time. The break-in may not be in the equipment, it may be in your brain. For example, you may find yourself focusing in on aspects you like. Practice makes perfect, maybe applies to selective hearing?
Or, if it is tube characteristics changing, maybe it is running at a different voltage than the other amplifier.
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