nikongod

Happy Birthday!

Are you using both channels (+/-) on the same board? IE left and right amps. Do you have the input caps in? I would ask tangent in a bit

what happened? to answer the Q on the previous page, 2*33Kohm is a good starting point for a 50Kohm pot.

Its about time you came around In the balanced configuration the pot does not have a ground connection. The 1Mohm (or whatever value) resistors at the input of the pimeta will provide a ground reference. I dont have a drawing, but hopefully this will help: pins 3&2 tied together, with a resistor between the pot and the XLR. then off to the side goes the output exactly like whats on pin1. I always wire it backwards the first time (when volume is at minimum the resistance between the 2 resistors should be minimum where connected to the pot) so it may be best to test with sacrificial headphones. Balanced Koss FTW! with alligator clips you can just use one side of the headphones just wire tip and ground to one channel of the balanced amp.

hehe, add up the price of all of the options. For the same price as upgrading both sets of caps you can have the BHSE with no caps. No cap is as good as no cap at all. The early speculation & guesses was that it was going to be a Stax-SRX/SP ES1 which does not require output caps. The nice thing about using output caps is of course that the amp can be made self/auto/fixed-biasing. Speaking with Jack Woo about the amp, Im still not clear on what it is ( he said its basically a GES on steroids, but then what is the phase splitter tube that was recently added for? and how does the amp have balanced inputs: the GES circuit can not accept balanced ins... too many things dont add up. Most likely he just didn't want to tell me what it was, which is understandable because nobody {except nelson pass who dosnt seem to care at all} likes people looking at schematics for amps they are trying to sell. ) but he did tell me that the output uses plate chokes which is pretty slick. Dunno if its slick enough to justify the use of a second set of caps in the signal path, but slick. Perhaps its something like an SRX/ES-1 but built with a single supply? aaah, the rampant speculation continues.

Happy Birthday!

happy Birthday !

happy birthday!

A thread for impressions on the Grado RS-60, a hybrid of SR-60 drivers and an RS-1 made after the RS-1 drivers were destroyed in an accident.

http://www.youtube.com/watch?v=1AiYaSyXcg4

My first camera was an AE-1, which was formerly owned by my mother. I used it primarily because it was affordable (free) and accessible (sitting in a closet for eons unused). I think when I found it the bag had the camera, a 50mm lens, and an 105mm lens. A nice starter rig. I later saved up and bought a 35mm lens to round out the set. Zoom lenses are for pussies (I could not afford one at the time) so I said fuck that noise! (damn I wanted one bad!) I must say that the little beast did its thing well despite being built by the wrong company. I have some strong reservations about the functionality of the light meter when trying to operate in manual mode: it really sucks! The light meter shows what aperature it thinks you should use, but not what aperature you have selected... no match point metering of any type. In its primarily intended shutter-priority function the body was esy to use and pretty intuitive although shutter speed priority is kind of a weird system for learning: the AE-1P with aperature priority and a better light meter display is a far better camera to learn to shoot. The FD lenses are of course out of production, but the fact that nobody respectable uses them any more has driven the prices down. Not a bad deal if your trying to put an affordable camera system together. I must caution you that the AE-1 (and all of its electronic brethren) are known for getting ferocious shutter bounce which starts to rear its ugly head at fast (1/1000sec is fast according to this camera, ) shutter speeds and then slowly creeps down into the longer and longer ranges until the camera is totally useless with an obvious overexposure on the right half of every frame. When this happens you should just buy a Nikon F3HP or F4s like you should have in the first place considering how much nicer both are and the current used prices. Overall, for what it was, the AE-1 is a decent starter camera but you can probably do better. Ooh, shouldent this thread be in the miscellaneous gear forum or something if we are talking about cameras?

Happy Birthday Dan! have a great one!

Most people follow the standard set by the K1000 R+=3 R-=4 L+=1 L-=2 I have NO idea what colors are what in the cable any more, but don't be surprised if they don't make any sense (I think red is left, and blue right, WTF?) I just strip the bit left on the 1/4" plug and check that.

The benefit to slew rate from balanced drive comes from the ACTIVE stages. In the ZDT, the tubes are all run single ended. You get a few extra bonuses to bandwidth and slew-rate in a push-pull tube amp compared to a single ended one because of how you can build the transformer, but then we get into the whole single ended VS push-pull tubes debate. Its an ugly debate, the most PC thing to say is that both design camps have their own benefits and inherent compromises. does the amp sound good, and measure well? yes: enjoy it

happy Birthday!

sorry to hear that

Its a logarithmic scale on the X-axis because of how we hear. Every "fixed length" represents 1 octave: every time you DOUBLE frequency you get the same length. A linear scale would compress the info below 1kHZ to the point where you couldnt read it or make the graph so long as to be impractical. 1kHZ is the 0dB reference point by definition, weird that nobody's graphs line up that way. They probably set their equiptment for a specfic pair, and then drew the individual graphs without resetting the levels for each new one. If you correct for that, you have +1,-3db across the given range. Not exactly something to sneeze at compared to a real speaker in a real room. Senn and some others have argued that the dips at 2K-4Khz are there to counteract some funky ear canal resonances, so the response may EFFECTIVELY be even flatter compared to a real speaker system.

A thread to post photos of our dogs. Behold! Freddy! He is a Bichion-spaniel mutt we adopted when he was about 1 year old. As far as I can tell Im not allergic to him.

I dont think its necessarily the transformers, but the ways feedback is applied around the output stage and its driver, and the "unconventional" coupling network between the gain and driver stage. There are far worse things out there than transformers. so there are 2 separate circuits on the board where all the parts are doubled up? 2 rectifiers, 2 big power resistors, 2 big electrolytic caps, and 2 small films?

take a DMM, unplug the cable and measure all the connections. Every pin at the top should hook up to something at the bottom. or you could just plug the plugs into the headphone backwards. Thats the plug that says "R" in the earpiece which has the braile letter "L" as well as the letter "L". If the noiseless channel moves taah-daah! my bet is on the cord being defunct.

Have a Happy Birthday!

Happy Birthday! keep the tubes hot

I agree with the recommendations for transformer coupled tube amps and the RS-1 although I dont have much experience with the ones mentioned here. SET means that there is only 1 triode per active stage, and is independent of whether they are directly or indirectly heated. The DNA amp is SET for sure, with only 1 triode per channel.

happy birthday!~

AC heaters. Bias them 75V above ground. Tubes that hum with "biased" AC heaters are not worth using in an amp 1/8 as expensive as this one. People like to blame the amp when tubes hum with AC heaters, and you know MFR's NEVER like to use AC for this reason. The old hum-bottles some dude had that never ran noisy on DC are now noisy on AC heaters (durr) any hum is bad, and these tubes have been in his family for generations: his grandfather built them and smuggled them into the country! How could they be anything but great? The cheap SET amp with no global feedback he just bought hums like whoa with his priceless communist tubes. Its terrible customer service to tell these people that any of their gear is crap, save the phone call and complaint thread on the web, spend $5 on a rectifier and a cap, and use DC heaters. Whether DC heaters are any better with tubes that dont hum is of course a topic of long heated threads all over the place, but you have to be truly special to make DC heaters hum and thats all that matters when your trying to make a buck. The darkvoice threads on head-fi are great examples of this: my amp hums with some tubes but not others. Why does my amp suck? Its your tubes (OK darkvoice grounds their heaters which dosnt help the situation at all), but nobody wants to hear that because they were expensive NOS tubes.... The new design is an ACTIVE regulator with some feedback built in to get low output impedance, where the old one was either a source follower/capacitance multiplier or a shunt based regulator. The schematic KG posted up is 100% tube which I also think was the intent of the original PS, except his schematic is like 10milion times nicer on the patrick82 scale than even my optimistic guesses of whats in there. It means that the adjustments to voltage are no longer done in steps. Rather than what amounts to a "high/medium/low" switch you have a knob that goes from low to OMFGWTFBBQ!!!111 without steps. Unless Im mistaken you can also adjust voltage while the amp is on with this setup (cool as hell!). As far as the dual pot thingy, you have to find a pot like what is sometimes used for EQ controls for separte channels on cheap stereo amps: no biggie. They are abundant in old junk gear. You could also just use 2 totally separate knobs/pots. On that note, Im not sure that separate *adjustable* regulators for Gain and output are a GREAT idea unless care is taken to limit the range (and then why even bother?) for the regulator for the gain tubes. I can see hardcore failures if the plate voltage on the gain tubes comes up higher than B+ on the output tubes, or when the same plate voltage sets the idle current for the output stage unsafely high for 6sn7. Why not use something like this: The PS KG drew up, with the lower limit of voltage at 340V with a simple SS regulator LOCKED IN at 320V (or whatever mikhail used in your amp and 20V more from the tube regulators to the output stage, my numbers as example) fed off of KG's regulator. The whole mess could be built dual-mono and would never have the risks of funky/incompatible voltages outlined above. This adds some silicon to the circuit as a regulator, but its somewhat protected by the tube ( LOL ) AND makes the current draw from both regulators identical. with separate regulators for output & gain you have one regulating 20mA and one regulating 50-80mA. This would light up at 30-60ma per regulator (same current on both regulators, variance is the use of different output tubes ) no mater what.