rodman99999

Responses from rodman99999

... Should I be concerned?
Here’s a thread that mentions the Wolze as using two 12AU7s:      https://www.audioshark.org/pre-amps-9/wolze-triode-line-level-preamp-4421.html      Dave Wolze actually replied to the post and didn’t dispute the mentioned tube compliment.        ... 
... Should I be concerned?
btw:   What do you have to lose, by trying your Morrison?      I used to own a Placette Passive Volume Control.      Unfortunately; the rest of my system, at the time, didn't have enough gain, for the SPLs I enjoy, with many of my CDs and vinyls. ... 
... Should I be concerned?
Q) "Would it play if it was setup for 12AU7s with AX7s in it?"      A) Yes, it easily could. As mentioned; those two tubes are usually interchangeable.               ".... someone seemed to have a reference / familiarity to the preamp, and told me... 
adjustable "fixed" bias amps
Happy listening! 
... Should I be concerned?
".....would switching to a 12AU7 instead of the 12AX7 make a diff?"      Yes; in most cases, the 12AX7, 12AT7 and 12AU7 are interchangeable (gain factors of 100, 60 and 17 to 20, respectively).      That could actually be your best bet, but- check... 
adjustable "fixed" bias amps
If your amp is push-pull, there must be two 300b tubes per channel (at least).       If those two 300b tubes share the same bias adjustment, they’re splitting the measured current (ie: 50-60mA each). 
... Should I be concerned?
A suggestion: Turn the Parasound’s level controls all the way down and your preamp’s volume knob to where you want it, at what you desire as your highest/max position.      If you can choose, do this procedure in Mono mode.        Play what you kn... 
... Should I be concerned?
No, you should not be concerned.      You can either download or read the owner’s manual from Parasound, here: https://parasound.com/pdfs/vintage/hca750_1000om.pdf      You’ll find instructions, under Level Controls, on page 7.      Here’s a more ... 
Signal to Noise Ratio and Amplifier Distortion
Typically; you don't know what you've got, 'til it's gone, regarding noise. 
Signal to Noise Ratio and Amplifier Distortion
NOTE: Much better to use the search feature, in the top left of that first mentioned site. 
Signal to Noise Ratio and Amplifier Distortion
Here’s a site that should help you find your answers/definitions: http://www.digitizationguidelines.gov/results.php?gltext=Distortion&x=0&y=0     Just search for the likes of IMD, THD, SNR, etc (gotta spell them out, with caps, or search... 
Rolling pre tubes question
I can’t add anything, far as advice, to what mijostyn posted, but- that Brent Jesse Recording, Upscale Audio (Kevin Deal) and Vintage Tubes Services (Andy Bouwman) are all excellent sources, for noise-tested/rated tubes and accurate information.  ... 
Has anyone ever had to repair a Magnaplanar?
Good thing the kids didn’t starve, before they grew up and could make on their own.        They must not have been home-schooled.       Not that they aren’t a great value for the money, but- I haven’t owned Maggies for years, BABY. 
Hard of Hearing Audiophile.
Some years ago; I owned a California Audio Labs Delta transport and both their Alpha and Sigma DACs.     My first choice for an AES/EBU cable was a .5 M, Kimber Orchid.      Sounded horrible (which was diametrically opposed to my experience with t... 
Is Break-In essential and potentially dangerous for the Audiophile?
Yeah: tubed components that take a couple hundred hours to, "warm up"  (snort of derision).