Simply putting a microphone up to your speaker does NOT allow us to hear what you hear. -No matter who good your tannoy, amplifier, etc. If you are using valves, you MUST insert a high quality transformer stage between the final valve stage (i.e., the compensation/EQ stage) and your digital stage. This is because valves are VOLTAGE amplifiers, and, thus, are HIGH IMPEDANCE. Solid-State acts as a current amplifier, and thus, transistors produce low impedance output. In short, silicon and vacuum valve audio circuits do not play well together without an impedance matching stage. The impedance need not match exactly, as with an RF application. You need to simply NOT to load your high impedance valve line output with a low impedance transistor stage. A high quality line transformer is what you will need. E.g., a direct injection (DI) box. There is a fine stereo DI box for your situation that sells for about $240 . This will allow you to make digital transfers without loss AND it should also remove that HORRIBLE 50-60 Hertz HUMMMMMM -you so obviously have. No one likes power supply HUM. No one. Yet, if you know what you are doing, it is easily eliminated. Alas, you have HUM. Just listen when you lift the tonearm off the record! This is being caused by a GROUND LOOP (this often occurs when trying to match disperate impedances). Your preamp or power amp probably has a ground loop via the power supply because you are not using a "floating back panel" on your preamp's back I/O panel. Somehow, I just know this. No, it's not a lucky guess. You must seek to ground each stage of your circuit to the same ground point, in your power supply section (including the I/O panel). Usually, a point near the second electrolytic filter stage work best. Also, if you use a seperate heater transformer and simple LM417 chip to regulate your preamp's heater power supply, your preamp's hum will reduce and the bass transients will dramatically improve. You will want to keep all these ground wires the same length, bound together, and experiment a little when routing them. Initial valve phono stages are HI-MU and often reveal ground loops that line level stages will not. Such stages also produce strong inductive fields that carry hum and other noise. Shielding and careful grounding are the way we solve such problems. An isolation transformer at the line output, can also relieve this problem. My preamps are all older valve McIntosh, and they standardly use a cathode follower isolation stage. -Works great on isolation, but can still not lower the output impedance sufficiently. I increased the coupling cap sizes, but getting much below 40,000 Ohms is not possible without losing significant gain. A Direct Injection "DI" transformer is your best solution, -if you want to make professional digital OR analogue transfers from your shellac collection,...or SHARE YOUR MUSIC WITH US! You do want to SHARE music, right? That's why you are making this post, right? No matter HOW well you think you are "miking" your speaker, there is no way WE can hear what YOU are hearing. Sound does not work that way. Even if you build an expensive anechoic sound chamber, and used the finest Ulam condenser mike in the world, you would still not be able to match the performance of direct connection to you preamp stage via a DI transforming box. YES, technically, there is loss in a line transformer, however, the loss is NOT audible to ANY human ear. If you don't like line transformers than don't use valves. Your valve power amplifier necessarily has an OUTPUT TRANSFORMER (whether you know this or not), that directly feeds your speaker. This transformer causes FAR more phase anomalies, THD and IM, which produces far more fidelity loss and sound colouring than ANY DI box. Impedance matching may also be done using a solid-state Op-Amp circuit, however, this will end up causing new problems. And you will still need to EQ the transfer. Op-Amps are really not the answer. Heck, the average phase splitting stage in a valve amplifier causes significant phase distortion, unless you are using 1% (or better) metal film resistors. Even then, a $200 class D power amp (made within the last 10 years) will outperform ANY valve amplifier. If I switched your valve amp with an inexpensive class D amp (hidden inside the chassis of your valve amp), you would spend a half hour of pure joy, thinking that all the problems with your valve amp had magically repaired themselves. I know one thing. That HUM bothers the heck out of you.
I’ve been looking for this at the vinyl shops, no luck. Glad it’s here. So much to learn from as I play along, phrase by phrase, trying to get it right. In my own way of course.
It' not clear: It's Dimensions & Extensions, right? So why does it say "Unissued?" (Working on the PDF update to my Sam Rivers book, so would appreciate a response.)
One reason to ALWAYS check for good music on RU-vid! Such a rare find, talent, video of an turntable doing its thing, and did I say TALENT yet? I did. Very good. Okay, so let's see thousands more up-thumbs for this!
@@tarocross8636Nice! Does 6 grams not ruin the records grooves? I have a Triotrack Suitcase recordplayer from the 50’s with a ronette 284 OV Mono cartridge with a 1 mil tip as well. New old stock needles. I track at 7 grams, should I get it to 6 grams to be sure not to damage the vinyl?
I used GE VR cartridge here, GE manual recommend 6-8 g. Therefore, I use 6g for vinyl disc and 8g for shellac disc. The vinyl grooves expand and contract so I think 6-8 g is fine.
