I've actually been on sushi service for awhile. But I'm a master of brunch, I used to run egg station at a top10 in the USA French brasserie.
Got the TT and phono today and just hooked up. Got the wrong phono xlr mini,will return for the right one, but using now with the supplied one for RCA, it's OK, will test out the Sumiko Moonstone mm cartridge. Listening now, a big improvement over the lp140xp with xp cart with ml and AT peq30 phono...definitely worth it...will be better yet I get the right cable and everything dialed in with MC.... Will put this sumiko Moonstone on the lp140xp after I get the new cable in a week or so.
Congrats, Chef. Keep us posted! If I may ask: Above, it was mentioned a few times that cartridges, by their nature, produce a balanced signal. Is that a definitive fact, or were folks speculating about it? If fact, then just running a DIN-to-XLR cable between the tonearm and the phono preamp would create a true balanced connection, correct? (Forgive my ignorance on this stuff!) THANKS.
from what I gather is only MC carts are truly fully balanced and most manufactures recommend actually using the RCA outputs for MM even on the fully balanced topology units. I don't really know the specific but seems pretty universal from what I can find from the manufacturers I've talked with. But this turntable , phono and cartridge sound great so I'm not bothered with trying to figure it out. I'll put on the AT-33SA when I get the fully balanced XLR cables which I ordered today. the Sumiko moonstone is a really nice MM cart, very impressed, I can't wait to see how it sounds running on the LP140xp and peq30 to really quantify the upgrade. but even sounds like tapping on the dust cover are virtually inaudible compared to what I would hear on the lp140xp.....so that mass effect is real....the pro-ject x8 and phono ds3 are dead silent and sound fantastic.
Yes, most cartridges are by design balanced since they are just a coil of wire with no reference connection, so a 5-pin DIN to XLR cable (with tonearm ground on DIN side only connected to the cable shield and XLR grounds) would make a balanced connection to a supporting phono preamp, but you need to verify that connection on the phono preamp will provide the correct loading for the cartridge you are using, some may only support LOMC carts. The only issue on some MM carts is that the metal body around the generator is connected to the right side return pin, so that link should be removed for best results, as shown below ...
A cartridge is a transducer, like a microphone. It carries and transmits a current loop, a single circuit over a pair of wires. The current going through one wire must be the same as that in the opposite direction; any less is a short or open circuit. This will develop a voltage if the current potential of the motor is put across a load instead of flowing freely through a loop. A speaker is also a transducer. Are your speakers "balanced"? How about if all the ground connections on the amp are the same ground? This is similar to differential signaling, but has a distinct difference, in that there are not two separate driven signals, nor would we necessarily separate them. Take for example an Ethernet receiver. There are two separate voltage amplifiers when transmitting. One goes positive while the other goes negative. You will see in reception it uses center-tapped magnetics to reestablish a common ground reference centered between the pairs. The signal level of individual pairs are then decoded - in reference to the ground signal. This is not how you make a phono stage. There is a single voltage difference to be measured. Separating the tiny phono signal into two halves for two identical amplifiers, in reference to a ground, gets you two signals half as loud, while connecting to two input devices (amps) instead of one gets you double the current noise. Lots of manufacturers simply stretch the truth, or don't know the terminology. Differential pair, balanced pair, balanced amplifier, these all mean something different. If they don't internally have have two identical input stages, two identical RIAA circuits, each creating output signals of opposite phase, it ain't a "balanced amp" - and you probably wouldn't want that. A pair taking the same path has a characteristic - common mode rejection. Any interference picked up in one wire is likely picked up the same in the wire carrying opposite current. In a balanced system, this gives two signals with similar noise, which will cancel out when added. On a transducer loop, instead, inducing the same changing field around both wires simply causes no current to flow (until you get up to radio frequency wavelengths).
Sounds great! Why don’t you put on the AT-33 now to find out the differences between using unbalanced and balanced cables?
Yeah I can. Getting a feel for the sumiko moonstone on this setup...will move that over to the lp140xp and peq30...
sure but I also should give the MM a full evaluation on the TT and with the phono. might as well for a few days while its already on there....I'll be throwing on a MC cart that is twice the price of the Moonstone.
This set of statements is mostly false if I'm reading it correctly. Phono stages can indeed be designed to be differential (as opposed to single-ended, where one side of the input is grounded). Not all of them of course, in fact fully differential phono sections are rare. We started manufacturing ours in 1989... The problem with the above quote is the idea of the signal being 'split'. This does not occur. A differential amplifier is a single stage of gain, not two (a pentode can be used as a differential amplifier, which is how Philbrick, the first manufacturer of opamps, got their start). Differential amplifiers amplify what is different between their inputs so the cartridge signal is simply placed between them and it amplifies. Potentially you have up to 6dB noise reduction per stage of gain by doing this- the key being an effective constant current source. You could use an input transformer with no center tap and it would be very effective (but since we are the 'transformerless guys' we opted to do without). You can argue that the input resistors needed to bias the input tube of our circuit is the 'center tap', but if the tube did not need the bias we would not need them. In effect they decrease the CMRR of the circuit so they have to be matched (in practice differences between tube sections dominate the limits of CMRR performance; for this reason we get as much gain out of the input circuit as we can). Equalization can be done in the differential mode with no reference to ground. This eliminates the need for matched EQ sections for each 'half' of the circuit and prevents any artifacts as the tubes age (and they tend to age to a more balanced operation over time). The advantage of amplifying a phono signal differentially is less stages of gain are required so potentially less distortion is generated. The tonearm interconnect cable will have less artifact (for those that audition phono cables for the 'right' one, this is valuable since a properly built tonearm cable does not have to be expensive and will sound as good as the most expensive out there...). In our case the phono stage can work with almost any LOMC cartridge and has only two stages of gain, including passive EQ.
That's a normal single-ended single-stage phono preamp, using the second half of a quad op-amp for subsonic filter. It has a balanced line driver IC for each balanced output, which he says measure worse than the straight RCA. What's going to make it measure worse is the basic power supply and rectification in the same box from an AC low-voltage input. Bare terminals were common in facilities like radio stations. No need to pay for a bajillion XLRs when you can use a spool of four-conductor cable. The problem with those reviews for phono is it completely discounts the careful balancing of current noise to voltage noise by designers to obtain optimum performance with the impedance and thermal noise of an actual cartridge. Common mode rejection can be far higher than 6dB, don't sell yourself short. However, you don't get your 6dB rejection gain without the doubling of peak-to-peak voltage between conductors/circuits, which a cartridge doesn't do just because you ask. And for uncorrelated self-noise of futher balanced electronics, it's more like 2^1/2 improvement, similar to parallel amplifiers in phase. Here's a rhetorical: does each conductor from the cartridge get to its own grid in the same manner, with identical capacitance? Is the output of the circuit naturally balanced without needing a phase inverter topology?
You misread. Our CMRR is in the 90s. What I was saying is the noise of each stage of gain is potentially up to 6dB lower than the same gain stage running single-ended. The cartridge connects to pins 2 and 3 of the XLR. Pin 1 is the tonearm ground. Pin 1 and pin 2 each go to a grid of a tube (or tubes) with very similar capacitance along the way (which in total does not exceed 30pf); so 'yes'. For this we like to see tubes with matched internal sections, fortunately surprisingly easy if we use common 12AT7s. If by you mean the output of the phono section, the answer is yes. Its still 'yes' if you meant the output of the phono cartridge.
It’s unfortunate that many fail realize that phono connections can be “balanced” via RCAs as long as the signal grounds aren’t polluted with chassis ground - either at the cartridge (pins) or along the signal wiring/cables. I’ve always appreciated this with the cables SME provided where the center pin is XLR pin 2, the outer shell is XLR pin 3 and XLR pin 1 is provided as a shield wire (drain) exiting the connector’s rear - floated on its upstream input, eliminating potential ground noise. Their chassis ground is on a dedicated lead as it should be.
Nice Chef... I love the 33 series - I own the 33Mono, AT33PTGii and the 33ev. Capable of wonderful sound when dialed in...
Thorens TD1500. EISA winner and winner in reviews. Fully suspended turntable, low w&f, excellent speed stability. Great tonearm. Test Subchassis-Plattenspieler Thorens TD 1500: in Tradition des TD 150 - LowBeats Or the TD1600. Also EISA winner. Great reviews. Here’s a test of the semi-automatic and more expensive TD1601 but they are the same, only the semi-automatics that differs. Erster Test Thorens TD 1601: die Legende TD 160 reloaded - LowBeats And add a balanced phono pre of your choice. Pro-Ject DS3B, or RS2/R3 are good choices. Or Musical Fidelity MX-VNYL.
Thread back from the dead. The project x8 has been a dream paired with the ds3b phono its exceptional....the ds3b also let's you hook up 2 turntables 1 xlr and 1 rca and it also in the manual says it's OK to hook it up to 2 amplifier or source inputs....so you can double up, they are always both hot outs. Here is a recent YT rip I did using my new TEAC W-1200 tape decks PCM / USB output directlyinto my phone...I use the 2nd rca out put as a feed into my tape deck side for recording and the XLR into my freya for in house listening. If you got time listen to this whole recording fantastic album
