doctorcilantro

Okay, I'll check with the PC or my Tascam tonight. Would creating a mono recording (in PC wave editor) of a mono record be essentialy identical to flipping a hardware mono switch; I assume it is the more I think about it. DC

My preamp has a mono switch, but I am embarking on a project that would mean not using this particular pre. If I create a mono recording project on my PC, would this be the same as using a mono cartridge or a mono switch a pre? thanks dc

Thanks. So would it further important to match the Contour tube to the other two? On another note, I just adjusted the trim pots on my DAC1 output. Previously, going to my mono-blocks with an input sensitivity of 1v, I had .880v at about 2 o'clock on the Sunfire preamp master gain. I didn't have enough headroom and never could use the volume above 10 o'clock.Carver discusses a few disadvantages of this situation in the manual, so I re-adjusted the system to have: DAC1 outputs 265.5mv per channel into Sunfire Sunfire outputs to Quicksilver mini-mites: 9 20.5mv 12 122mv 3 323 MAX .995v Things sound sweeter already and I really enjoy the greater control of the gain (more steps?) So......a friend of mine asked: "A max input signal of 1.2 Vrms shouldn't clip the inputs on your Sunfire....I didn't look at the manual, but it should handle that signal level easily. Where do you run your volume control, though? My measurements of several preamps and the pre-out of an NAD integrated showed that the "zero gain" point is usually around 1 to 2 o'clock.....so if you run the knob lower than that, the preamp is actually attenuating the input signal, sending a weaker one to the power amp! (The specs on the Sunfire show the line input gain to be 12 dB, that's a voltage gain factor of 4, so it would drive the outputs to 8 Vrms with the knob cranked to the max with a typical CD player input....and that's what my Musical Fidelity CDPre24 was spec'ed at, within a couple of tenths Vrms.) For the life of me, I fail to understand the decisions about the relative gain of devices in the chain these days. It does make sense to increase the voltage out of a CD player or DAC.....thus placing the signal higher above the noise floor.....versus what typical old phono preamps put out, which was usually less than 1 Vrms on a test tone, or tape decks that were designed to put out 0.775 Vrms when the VU meters were at 0 dB VU. But those were not hard upper limits as is 0 dBFS in the digital realm...there was headroom above the 0 dB references in those days, because 0 dB wasn't referenced to a constrained maximum level. I really wish I knew why makers construct power amps that clip at 1 or 1.2 Vrms when preamps can put out 8 to 10 Vrms. The current generation Quad SS amps clip at the old 0.775 Vrms standard that was typical in European gear for many years....that's ~ 8 dB less than a CD player puts out! Many users end up having to add fixed attenuators between non-Quad preamps and the 606 or 909 to avoid hair-trigger volume control. Power amps could be designed for 8 to 10 dB less gain in most cases and probably be even more usable as a result--finer volume control over the range of CD's that are mastered all over the place these days. Maybe it's to give the user the perception that if the system is loud with the volume control at 9:30, it's great because that means there is a lot of headroom available.......when in reality, it just means you better not go above 1 o'clock or you will damage your tweeters in a hurry!" dc

Hi all, I own a Sunfire Vacuum Tube preamp and it has a simple EQ ("Contour Control") with treble and bass, which is activated by a switch. The driver stage has (3) 6922 and the manual states that one of these is for Contour. Can I run this pre without this tube for the Contour if I don't use the EQ. Not knowing a lot about this stuff, I was wondering if this third tube is just for EQ are what I have called a phase splitter. I called Sunfire, but as they don't make the pre anymore, the tech really couldn't tell me a lot at all, and I decided not to push the issue. The manual is here: http://www.sunfire.com/pdf/Classic%20Tube%20Preamp%20Manual.pdf thanks for any help! jon

Probably should have been more clear and excluded mention of the unmod. grooves. I think I see what you mean though. The two are seperate, the "noise" in the preamp circuit and the gain applied to signal. So if I bump up the gain 10db I won't neccessarily see the "background" (noise seen with no-inpu/playback) electronic circuit noise go up 10db. Effectivly, I would get a better SNR? thanks Larry. DC btw- it't not audible but about -65db on the Wavelab vu (PC wav editor); I would like to record a little hotter and listening volume could use a boost.

I thinking about utilizing higher gain in my moving coil stage with a resistor change. The stock setting is 60db with 65 and 70 as options. Dumb question, but if I bump up the gain, am I likely to see a higher noise floor out of the preamps tape out? The manufacturer simply states the phono stage has better than -78db snr. Would this apply to the other gain settings or must it change as a result and raise the noise floor. I'm hoping it won't but almost inclined to say that will. that said I have run some tests with unmodulated grooves and the noise floor is mainly just low frequency stuff i.e. rumble and surface noise. http://digitanalogue.blogspot.com/2008/08/hi-fi-news-analogue-test-unmodulated.html (if your interested) dc

I was using the MM stage. When I switch off the 6922 (which piggy-back on the MM 12AX7) I can see closely matched average RMS levels. The (2) 12AX7s are from Upscale, but I also trust Jim McShane who sold me the EH 6922s. I moved some tubes around and the levels are closer but now noisier. When a manufacturer states "noise better than -78db" for a phono stage, can you simply observe something close to that with no input singal? IThe Grado Reference should not be introducing noise to the signal, not this much, something doesn't feel right. I'm going to roll in some various sets of 6922 tonight. Jon

I have some Amperex (various makes) 6922 and I keep them in the line stage. Now that I'm using the moving coil I need some good tubes. I tried some of my Amperex in there and while super microphonic (booming to the point of an echo when I rapped the preamp housing) they sound was so much better with them than these EH 6922. I am going to do some heavy listening with Amperex, EH, and Sovtek in the Mc this weekend. I swear there was a major differece; I need to make sure my tonearm/tracking force didn't get out of alignment. I'm looking at Tesla 7DJ8 w/ low noise and matched right now but tempted to buy some Telefunken 7DJ8/PCC88 for less than half the price of the Tele E88CC. I found some info on AA about the 7DJ8, all quite positive, especially the Tesla...for the price might make sense. DC

I'm real interested in trying these out in my Sunfire moving coil stage. I have heard they do sound great even when undervolted, but on AA some were discussing they could sound even better at 7v. This is a high gain situtation which I was considering upping further to 65 or 70db. I'll report back after testing these. Sunfire couldn't give me any info over the phone as to the rated voltage (6.3?) for the Classic Tube Pre which uses (4) 6922/6DJ8 (one for "Infrasonic filter) and it also uses the two 12ax7s from the MM stage. DC

I was wondering if anyone has an opinion on the following: Measuring input into my PC and using Wavelab, I see a 8db difference in average RMS when monitoring the moving coil of my Sunfire pre. The (3) EH 6922s I just got are matched. Should I be seeing a more uniform average RMS (not talking about the peaks)? I have also looked at the recording of a 1kHz test tone played back from vinyl and saw a 2db difference; I don't think this is due to the cartridge alignment/azimuth but as you can see this is another possible variable. The Hi-Fi News Analog Test Record has an azimuth test; you listen in mono and adjust cart until the signal sound matched through speakers/headphones, but how would know if the phono stage was imbalanced with regard to gain on each channel. Is the attribute good or bad for a phono stage simply a question of SNR, or with tubes is there always going to be an issue here due to how closely matched the tubes are? So is this even feasible? I moved the 3 tubes around and at one point the difference was smaller but still substantial. Would matched tube show a matched RMS "at rest"? Assuming the phono stage is working properly which would be hard for me to verify, isn't this why we match tubes, to match gain? I may try take the output from the tonearm's RCA box direct to PC sans phono stage to see what's going on with the cartridge, I could boost the signal in Wavelab and would I expect to see the left and right channel with the same balance. Or should I be testing average RMS by using unmodulated grooves on my test record. Probably getting way too anal about this, but the original imbalance was substantial. dc

IIRC, the weaker the signal, the more suceptible it is to the affect of high capacitance. A real shot in the dark here, could we say that the higher the capacitance, the greater becomes the wire's ability to impede and reduce the signal (bigger the battery the bigger the charge it can "hold"). I wondering if you start with 3pF and go up to say 75pF on one particular system, before real detrimental effects (coloration? distortion?) kick in, are we simply going to observe a change in gain; and would that be rather minimal or substantial given a low output .3-.5mv signal? dc

Mike Morrow reports that "after re-measuring, they are .01nF per meter - so a claimed 3.3pF/foot. My question is, does one really need cap. that low? I happen to be using a low ouput Grado and wonder is there really any sonic benefit (with an already short cable run) given the acceptable ranges of capacitance above, say 30pF/foot. DC

I agree about the saltiness. And .1nF is probablywhat they mean; then it's about 33.33pF (about the same as my current cable). pico-farad (pF) nano-farad (nF) micro-farad (mF,uF or mfd) capacitance code 10 0.01 0.00001 100 15 0.015 0.000015 150 22 0.022 0.000022 220 33 0.033 0.000033 330 47 0.047 0.000047 470 100 0.1 0.0001 101 dc

Understandable, but these appear to be rca interconnects for phono use (?): http://www.morrowaudio.com/ph1phonocable.htm DC

uF/ MFD nF pF/ MMFD uF/ MFD nF pF/ MMFD 1uF / MFD 1000nF 1000000pF(MMFD) 0.001uF / MFD 1nF 1000pF(MMFD) If someone claims their phono (rca>rca) cable has 1nF of capacitance per meter....isn't this rather high (1000/3 = 333pF/foot)? I know Blue Jeans Cable sells a 30$ interconnect that has 12pF/foot. Am I getting this right? DC

I should have been more clear. I was talking about the MR-1>PC Hard Disk transfer. What's the typical filesize you end up with for an avergae length LP side? Glad it's sounding so good. Nice to be able to archive and also "take your vinyl with you". May be you can find a demo of this; it's pretty nice NR software: http://www.algorithmix.com/en/descr_pro.htm DC

Mallette - are you recording DSD? You are recording to the MR-1, connecting it to your PC, transferring the file to your hard drive, converting the file to PCM, then editing the result? So you can't record to disk through the MR-1? Wouldn't really expect this I guess, but would be cool. DC

Archival of your material is within fair use I believe; that's why programs like AnyDVD are still on the market. DC

I'm guilty but personally, I don't burn CDs for myself anymore; friends, collegues, yes, but even then I get asked to "here just put it on this thumbdrive". But I do enjoy making mix CDs, printing to disc a cool cover, and mailing them to unexpecting friends, so it's not dead yet. The Lavry AD-10 doesn't do DSD but what it does it does well, and the workflow will be SO much easier. Granted, if I really needed a field unit, the MR-1 might be the only way to go. I could do 24/44 or 32/44 for vinyl and just higher bitdepth for any noise reduction or EQ, but most likely I'll just do 24/96; I don't do much editing (NR or EQ) anyway. I wonder how easily one could mod the MR-1 with a larger HD; an SD slot would have neat-O too. DC

EMU doesn't offer 88kHz nor 176. Playback goes out to a DAC1 and I find that 24/96 is a pragmatic medium and a good compromise. 1. I can leave these files as is, and avoid any dithering or sample conversion reducing my workload. 2. If burning, I can convert on the fly with J. River's DSP and while I agree that 88 would avoid any errors, I'm confident I'm not going to notice them. 3. The CD is almost dead. (even though I still love casette and CD mixes) I upsample all digital audio to 24/96 for playback, I do it mainly because I'm lazy. People argue it can push the noise floor up futher out of range, but doing this I can have native 24/96 material played back with any resampling and the rest is upsampled. It's also painless to do with J. River for audio and FFDshow for video (with low cpu usage for both). Other wise EMU patchmix has to be changed manually to 24/96. The AD-10 is probably big time overkill for vinyl archiving but I've got my hands on a pretty nice phonograph system. dc

Fascinating article regarding DSD & PCM: http://homerecording.com/bbs/showthread.php?referrerid=47402&t=179930 I'm considering a Lavry AD-10 for vinyl archiving (I currently use an EMU1212M(. The Korg MR-1000 is interesting, and while cheaper than the Lavry, the AD-10 will be easier workflow going right into the EMU1212 optical at 24/96 and right into Wavelab. I keep vinyl archives at 24/96 with minor noise reduction if needed (no normalization or compression). The MR-1000 conversion from DSD to PCM is probably overkill for my little archiving project, and even the AD-10 probably is. However, the MR-1000 can record PCM at 24/96 as well so maybe I should consider. I do like the idea of the Lavry avoiding USB and using optical though, which facilitates the aformentioned workflow, and avoids the pitfalls of USB. DC

"The E.P.A. recommends taking action if radon gas levels in the home exceeds 4 picocuries per liter of air (a measure of radioactive emission); about the same risk for cancer as smoking a half a pack of cigarettes per day. In Dr. Sugarman’s kitchen, the readings were 100 picocuries per liter. In her basement, where radon readings are expected to be higher because the gas usually seeps into homes from decaying uranium underground, the readings were 6 picocuries per liter. " Yikes......but more importantly, how does radon affect room acoustics [] DC

I downloaded their (his) new album for free online (24/96kHz) FLAC I believe. Haven'tgiven an ear yet though. DC

Same here. DC

The granite is real pretty; seems to match the Khorns color black grilles/brown wood. How did you mount it on the base? I got lucky when my in-laws got rid of their granite island in their kitchen - they gave me the piece and it's atop my reconfigured rack. DC