sunnysal

thanks. are you using upsampling or not?

D, let´s start with DAC you are using, what source components and connections and then we can be more specific. many digital formats that are used for videos are not supported by audio DACs. regards, T

what setting did you finally settle on as the best sound for you? T

if you dont hear it, dont worry about it and move on. I got to a certain point with both the ICs and speaker wires where I stopped hearing anything significantly different in my auditioning so I stopped. I am happy with my system as it is now. I would note that for me, in my system, with my equipment, with my music, tube rolling, swapping amplification and source components all had more dramatic effects than any changes I made in wires. YMMV, IMHO, yadda, yadda. enjoy the music! tony

gratz! let the fun begin! I want to hear how the different settings affect the sound. give it a good work out and let us know your thoughts. warm regards, Tony

we agree that keeping the volume set high is key to success with digital volume controls. the problem I have in my system is that my speakers as so efficient I need to keep volume WAY down to listen. this is practically the only thing that has kept me from trying to eliminate my preamp and using a digital volume control on a DAC. I am anxious to hear about the M-DAc which seems like a cool unit. regards, tony

another comment from your friends at wolfson: "Another drawback of digital volume control is that the signal-to-noise ratio (SNR) worsens at low volumes. This is due to the quantisation error, which is inherent in any digital system and may result in audible noise. Its magnitude depends on the resolution of the digital audio data and/or the DAC. High-end audio systems are designed such that any noise is negligible compared to the magnitude of the audio signal, and therefore inaudible. However, when volume control is performed in the digital domain, the digital audio signals amplitude may be decreased by several orders of magnitude while quantisation noise remains constant, resulting in a lower SNR" p.s. just hit 3,500 posts. great to still be learning and sharing so much with friends here on the forum after all this time!

thanks for the follow up, interesting conversation there. too bad he didnt give much information about the output stage to see how it is implemented in that unit. regarding digital domain volume control I think you need to hear both sides of the argument, the designer doesnt really give you a very scientific explanation about why he prefers it to analog. let me try to add to the issue by quoting robert hartley "Reducing the volume in the digital domain is accomplished by multiplying each sample by a number less than one. Let's take the example of decreasing the playback volume by 6 dB. Because 6 dB represents a halving of voltage, every sample is multiplied by 0.5. The samples encode a number that represents the original analog waveform's amplitude at the time the sample was taken. By mutiplying each sample by 0.5, the amplitude of the econstructed analog signal is reduced by half--or 6 dB. But there's a price to pay for this digital slight-of-hand. Every 6 dB of attenuation reduction in volume) reduced the playback system's resolution by one bit. In other words, a 16-bit signal atenuated in the digital domain by 6 dB now has the resolution of a 15-bit signal. Lower the volume by 12 dB and you have the equivilent of a 14-bit source. Dynamic range is reduced, and the music signal gets closer to the digital noise floor. With fewer bits, low-level signals can become more coarse, particularly at high attenuation levels." interesting huh?

not considering a DEQX? aussie developed and quite a good active. tony

Congratulation on the k-horns! definitely get them into corners, the bass will thank you. Don´t plan to do anything to them re: crossovers, drivers, wires,, etc. until you have listened to them a LOT in your system, with your music. once you have a better idea of what you feel the shortcomings are then you can plan mods to address those. enjoy the music! T

AC current and high frequencies would be most affected by corrosion on a wire´s surface. DC at audio frequencies MUCH less so. however given the extreme eye for detail many audio lovers have it is not impossible to assume that people would want to maintain nice, shiny., corrosion free wires. needless to say corroded connections are a problem. T

I owned a pair of MG-1c just before acquiring my klipschorns, they had great resolution and sound "fast". they were a little light in the bass for my without the huge impact that big woofers or horn loaded bass horns can provide but then again that is why we buy these klipsch speakers. overall they were great speakers and I never had any of the problems you mention in your OP. I think the corrosion issue was more related to the ealier versions of the MG-1. it is true you need to treat them with care, not to be thrown around, etc. they DO need a hefty amp to do their stuff (I had a McIntosh SS amp hooked up to them). for $150 it seems to me to be a no brainer. regards, tony

both the peachtree Dac.it and audiolab Mdac use sabre chips (though the peachtree uses the higher end sabre chip), you are right that the same chips appears in some of the highest priced DACs in the world. I like the "play factor" of the audiolab unit allowing you to choose filters, etc. and it seems to use fairly high quality components for the price, I don´t see much about it´s output section and since it acts as a preamp it would be nice to know about how it generates and manages its analog output. I also cannot see much listed about the power supplies. I have always liked the rotel "sound" so if their DAC keeps those same family values it should be a smooth, warm sounding unit. tough choices, becuase there are a LOT of options out there. I suspect you cannot go wrong with any of the ones you listed. one last note many people classify the sound of the sabre chips as analytical while the wolfson might be considered smoother. YMMV, etc. given the flexibility of the audiolab to tailor the sound in your system I might think it owuld be your safest choice of the group. let us know how this progresses. warm regards, Tony p.s. just to complicate things more add the rega dac to the list, really good output stage implementation there.

I think your worst case scenario is that you have used up some of the useful life of the tubes, in tube preamps the useful life can be arguably decades. I would not anticipate any damage done by leaving the preamp on for a long period per se. Since we don´t know make and model of preamp and amp, nor type of tubes it is hard to give a more specific opinion. do have a set of replacement tubes on hand just in case, which is a good policy anyway for tube amp owners. let us know what happens the next time you fire it up (forgive the pun!) and listen. regards, tony

looks great! so you leave some pins off the EL84 and run them "triode"? regards, Tony

the SETHs look great. the magnequest site still has the parts list and schematics for that one. the WE91 is a really good PP DHT, schematics of that are public domain I think. tony http://www.magnequest.com/diy_lessard_2a3pp.htm maybe jeff is still around somewhere?

I feel we should take it slow when modding. listen a LOT before deciding what areas need attention and then work out a plan to address those identified weaknesses. In the end I ended up satisfied with my sound. BTW I am using a PP 2A3 rig and love it, more than enough power to rock the house. regards, tony

this is a cool comparison of features of some under $1,000 DACs. https://docs.google.com/spreadsheet/ccc?key=0Av47ZDpoaXOydFFIaUh0QS0ybGZTOUNJaDEtQlhWV%203c#gid=0 peachtree, PS audio, cambridge and MSB all make great DACs but I personally I have my eyes on the following; http://www.lampizator.eu/newdac/lampizator/Lampizator_DAC.html http://schiit.com/cart/index.php?main_page=product_info&cPath=0&products_id=11 http://bursonaudio.com/Burson_DA160.html as I mentioned there are a variety of good chips out there, almost a flavor of the month kind of thing. the implementation of the DAC chip and the output stage really determine a DACs sound performance. like almost any other audio component, extensive listening tests in your system, with your music will decide which is right for you. not the selection via specs, chip type, etc. warm regards, tony

big topic. let´s start with price range, there are a variety of candidates depending on your selection of pricing. let me know what range you are thinking about and I will list some candidates with comments. the chip used is only one factor, the implementation of the chip has a huge effect on the sound, I would argue that implementation may have more effect 0on sound than the core DAC chip. regards, tony

I have done a number of things. added ALK crossover, tried triamping with DEQX electronic crossover , swapped tweeter for JBL2404H and ended up going back to the stock driver k-horns with the ALKs, too much trouble and management in the full house configuration (not to mention the reduced WAF) for what seemed to me rather modest gains in music quality. I might have even gone back to the original AK3 crossovers had it not been for the damage done to them during my first swap to ALK. not that the ALK dont sound good, they do. but the origianl crossover IIRC sounded somewhat warmer in the midrange than the ALKs and I liked that a LOT. sold the DEQX, the 2404Hs and other amplifiers in a closet somewhere and me enjoying the hell out of music played on my k-horns. T

nelson pass has some interesting testing and observations; http://www.passdiy.com/pdf/spkrcabl.pdf he found that at the extremes of wire configurations there were noticable electrical differences but that he could not conclude they would be audible, etc. also, there is some indication that too much wire can be worse than the "right" amount, various reasons are given: skin effect is mentioned, though this is usually associated with AC there are indications it can cause effects on DC as well, increased resistance and variations in inductance over distance could both be factors. Another factor mentiones is that in huge cables the quality of the materials and surface of the materials can be of a lower quality than with thinner wires with less material, contirbuting to perhaps negative effects. I personally would stay away from extreme wires, superthick, flat, etc. but since this is a hobby, I say to each his own. enjoy the music! warm regards, Tony

as mentioned old caps can go bad and cause a lack of bass...the HK 430 is a great receiver, I would even venture to say better in two channel sound than most options available today. Until you decide to send it out for new caps, look for the "contour" button ans see if that helps at all. regards, Tony

I would hook it up and listen for a good amount of time before deciding on rebuilding, upgrading, etc. I have a 730 that has been unrestored and it sounds just fine! I too suspect that it might benefit from some new caps, etc. but since the light work, the pots dont sound scratchy and the sound coming out of it sounds great I have not gotten around to sending it out yet. the same may happen to you. at least give it a listen before deciding. the 730 is a really nice piece, many think it is the best of the X30´s. warm regards, Tony

glad to hear you are aware of high voltage dangers. also really glad to hear the system is fixed now and you can enjoy it! regards, T

Congrats on the Cornwalls! many of here have had very similar "I found the sound I was looking for" moments, thanks for sharing yours. before getting into crossover changes, etc. give them a nice long listen. I would say a few months at least, to really identify what short comings you may still identify with this new speaker/system combo. Once you are sure what you want to change then you can consider the various options; source components, amplification, cables, crossovers, horns, drivers, etc., etc. the most important thing is you, like many of us, have found the sound you like, enjoy! warm regards, Tony