Quote: Yeah I suppose- it's just that it seems there is always a question about gain from someone and the advice is always something anecdotal and often the source (DAC) isn't even cited.  I may take all this info and see if I can create something useful w/ it for people new to DIY and...

Quote: That's interesting.  Any idea what the relative dB difference is between those 'quiet' albums and louder albums at the same volume pot setting?  I think if we could come up with a reasonable range of 'headroom' needed for various recording levels, we could come up with some solid...

Quote: I think you'd actually be fine for anything but a seriously variable collection.  The K702 is rated at 105dB/V, which translates into ~93 dB/mW efficiency @62 Ohms.  Based on your source you should only need a gain of 2-3 to get 115dB+ peak volume on normalized recordings.  How...

Quote: Thanks for the input, all.  Will revisit the questionable numbers.   Edit:   Okay I've revisited all of the numbers and corrected the sensitivities that were originally 1dB/V.  I have added a calculator to the spreadsheet to do that.   Nikongod- actually the gain...

Quote: I can do that if there's interest.  It's a series of pretty simple calculations but I've got them packed in a table for quick reference.

Quote: Sure.  I've upped the dB requirement to 115 for some additional headroom for quieter recordings.  In practice I've found this to be enough, but again YMMV.   I'd attach the .xls file instead of posting screenshots but I seem to have been denied that ability.  Sorry!  

Quote:   Quote: Where is your data showing that the amp does not, by spec, have enough output to properly drive the quoted headphones?   Actual power specs: 6.25 volts RMS on AC power at < 1% THD into 150 ohms 4.5 volts RMS on DC power at < 1% THD into 150 ohms...

Quote: Huh?

Quote: Fair enough.  I don't want to come across like I'm overreacting, was just trying to provide a parallel and it's a bit half-baked.

Hold on a second here- I'm a bit confused at the overall tone from the vets here.  Bear with me, please.   So the limitations of the input stage are being touted as a "major problem" for the DIY crowd because it requires some forethought and building the amp such that the gain is correct for...

Quote: I'm also interested to see this.  Did some quick searching (here and Google) and couldn't really dig anything up.  

I will definitely be building one of these.

Great to hear that it's up and running!  Enjoy your new amp- over a year after building mine I rarely go a day without listening to it...

Quote: You can (and I did as well).  What I was stressing earlier is that they are definitely not required, though some were giving Chrono the idea that they were.  Either way, that wasn't his problem so we can move on.

Good to hear that there are no issues there.  Check out the Troubleshooting section of the Initial Setup page on amb's site for a good start on what to check.   Other than that, one of the first things I'd check is the orientation of your trimpots.  I've seen a number of blown boards on the...