luvdunhill

Steve: Looks great!

nice! I think depending on your setup that the weight is absolutely necessary. I have a blob of blue tack on top of my cartridge and have no doubt that the improvements of the SB would be well worth it, as it has in the past for me.

he already has a top-of-the-line phono preamp*, why would he stoop down to this level? assuming the gear in his sig isn't totally made up..

I thought about that, I think that's a limitation to the AVC approach but not the the TVC approach. However, I found a 50/50% Permalloy and Z11 core that would not have the same saturation issues as a 100% Permalloy unit. I have an e-mail off to the manufacturer, so we'll see what he says. Since my power amp has no voltage gain, I think I may very well run into this issue.

only 60dB gain? For many, that's not enough gain for a LOMC, not to mention something in the 0.1mV range. The Xono with 76dB gain and for example the Klyne phono stages at 66dB+ gain are more suitable if one wants to avoid transformers all together.

60 Step Naked Vishay S102 resistor modules (as used in our TAP resistor Pre-amps).....$260 Those look like reed relays perhaps?

I'd buy an Ono and "update it". The circuits are very, very similar and the difference are well documented (by me).

don't forget there are 2 types of ModWright caps, the M and the T. The M Series Capacitors are made with a proprietary oil-impregnated metalized polypropylene dielectric with pure copper tinned leads. The T Series Capacitors are made with pure Teflon film and copper foil. You don't see the second label, but that's what's going on here. It's more obvious in these pics: http://www.modwright.com/pdf/ModWrightCaps.pdf Also, a general link on bypassing that's useful: http://www.northcreekmusic.com/Bypassing.html

deepak: nah, just get an Xono. It will handle down to 0.1mV fine. Remember, the specs of the Xono are at maximum output which is 20v (!). That being said, if I had to go the SUT route, I'd go with the CineMag. Torpedo: Just FYI, S&B will not sell direct to DIYers anymore. Also, Bent Audio is using the Slagel units now and are going to be offering a line of modules for DIY use. The resistive relay attenuators look very nice, and will be the upscale competition to the likes Twisted Pear Audio and Dantimax. I'd expect the new items to be only their website any day now (ooh, some already are!)

Fing: Are you looking to sell your TVC? I might be interested Although, I contacted Nickolas and he's willing to sell me the balanced TVCs naked for DIY use

Any reason a TVC couldn't be used between a preamp and the amplifier itself? Kinda backwards thinking I suppose ... but it solves the SE -> Balanced problem that AVCs have to deal with...

well, feel free to experiment. Since this is a phono stage, input and output connections should be as short as possible and power should be routed away from things and kept as short as possible as well (including connections to toroids, diode bridges, and the like). If possible, it would be nice to separate/shield the toroids more. Perhaps a tuna can or mandarin orange can could help shield them?

Thanks! were the AVCs wired for gain, or were they used passively, or in front of a preamplifier? I cannot seem to find pricing on the Tributes, so I've e-mailed them...

cool!! Here's my basic idea. Assemble the case. Remove the top and the back panel. Point the front of the case away from you. Stick the side of the PCB that accepts power towards the front of the case. Then shove the PCB in the bottom-left corner as far as it will go. The IEC inlet will be on the right and power cables will route down this side. Bolt the toroid(s) onto the front panel. Stick one capacitor clamp in the upper right corner and one in the upper left corner right up against the front panel and the side panel. Then mount the two bridges on the bottom of the case between the capacitors in the middle. Obviously, the front panel will look a bit lame with bolts sticking out of it, and that's where the wood comes into play

I think 2dB inductive attenuation is much finer than resistive attenuation, but I have nothing to back that claim up other than voodoo magic.

Do you know what transformer he uses? Assuming it's the same guy at DiyA, he's a nice guy ..perhaps he'd tell me

My hottest source is 2v. I'd assume that the (mostly) 2dB steps on this baby with a 2v source is different "feeling" than having a 5v source... I'm surprised there aren't more TVC/AVC proponents around here

for me, it depends on how the steps are spaced, not necessarily the number of steps... ~2dB may not be enough resolution, granted. check out the back of the pic posted.

yes, breatfeeding definitely helps the sleep schedule! as long as you don't roll over on the little one while sleeping

I'm sorta intrigued by this unit: anyone know much about it? Also, anyone heard the AVC TVC units from Diy HiFi (i.e. Django, etc.) 50/50% Permalloy Core Autoformer 28 step (Pair) | Diy HiFi Supply Of course there is the S&B, Sowter, and Jensen (and probably Lundahl) .. any others to consider? This would be used in conjunction with an active preamp. What is the general consensus of TVC used in this type of situation?

why don't you read all the project pages at headwize and see if anything fits the bill? Even if you don't find something suitable, the time spent reading will be well worth it.

I just sent out PayPal request for the remaining parts and the shipping. I have the kits in the car ready to mail. Please make sure you send your current shipping address, so I can verify it with the one that PayPal has on file. I didn't get around to matching the Toshiba semiconductors, but will soon. They'll come in a second shipping in a ESD bag, inside a Jiffy envelope. There "may or may not" be a few "d'ohs" in the BOM... we can discuss when everyone gets their parts. For those using the case I purchased, things are tight. I have sent a case to swt61 and instructions and perhaps he can post pictures when he's done mounting things. I'm notoriously bad at judging spatial relationships in cases, so it's nice to know a few more sets of eyes will be looking at the case layout aspect of the project. If you don't know what a particular part is used for, just ask as everything should have a use At the moment, the only missing parts not included that I know of are #4-40 screws for the heat sinks (you need 3 per) and hook-up wire. Please let me know if you find something else It's a very nice kit, and should be a very straightforward build. Thanks again guys!

yeah, stock idle heat dissipation is around 62 watts stereo. I have one channel running now on my bench and that's almost exactly what I got. I'm at around 22 C temperate rise above ambient. Once you get it, I can help you measure it and you can figure out exactly how it's biased and what it's output is and when it leaves class A. I'd personally turn it on for 12 hours or so and measure the DC offset voltage before I hooked it up, but that's just me being paranoid. Nelson recommends a few weeks burn in before being sure the DC offset is in spec, and somehow I doubt the builder did this... Another thing about buying on the "DIY-market" is that you really need a distortion analyzer to tune this amplifer, according to Nelson... that's the only way you'll get the specs posted, as he's been quite candid about that.

yup, 0.6 C/W per transistor hence the pair. Trust me, this builder had to of lowered the rails or this could be another example of epic fail. Also, everyone over specs what Papa recommends, as those strangely configured, non-conventional heat sinks he uses seem to have magical properties.