Hi all I’m going to build a PPA v2 powered with a YJPS psu and I’d be grateful if you could help me regarding several doubts. 1) I have two unused Black Gate series N non-polar capacitors. I had installed them at the output of a headphone amp but now, with a FET-input opamp in it and very...

Thanks for your response, Ti. Perhaps using in Cbb a very small cap, combined with the 50k log pot as variable Rbb and a gain=2x or 4x, would put the point “Fc”, from which the bass boost takes place, higher in frequency, to around 1k-3kHz. This way the behaviour of the filter is over a...

Hi all. I’ve moved this post to the DIY section of the forum. My apologies for the previous mistake. I’m going to build an AMB M3 Headphone amplifier, which probably will serve also as preamplifier section for a LM3886-based loudspeaker amp. I’m currently using another headphone amp with a...

this post has been deleted here and moved to DIY section

Thank you for your answer, Brian. I'm sure that the Ballsie module will sound a lot better than the stock Denon analogue output stage: better op-amps, independent linear power supply, no caps directly in signal path, no muting transistors, better PCB layout... BTW, in the assembled and tested...

Hi all Although this forum thread is for Opus DAC, I'm going to put here my questions, as I've read several posts regarding the Ballsie module. I’m interested in upgrading my universal Denon DVD-2930 player. I haven’t yet the Service manual for this model (do you have any idea about...

Hi all I’m interested in the Meier passive crossfeed circuit. I’ve made the Linkwitz crossfeed but I’m not using it because it dulls too much the sound and reduces the available volume a lot, although I like the way it places the soundstage “farther” from my face. I have read that the Meier...

Hi I have ordered several times from Welborne Labs and the only trouble I had was because my e-mail address (a yahoo one) was blocked (I don't know why) by some anti-spam filter in their website. Using another alternative (hotmail) address solved the problem. They also have made a couple of...

Hi I’m going to integrate a remote controlled stepped attenuator (a Welborne Labs kit) and an headphone amplifier (WNA) into the chassis of my amplifier (Copland ultralinear with a ECC83, two ECC82 and four EL34 valves). Believe it or not, there is enough space . The output from the...

Hi, I too have a doubt regarding the connection of headphones using 4-pin XLR connectors and not the standard “TRS” phone stereo plug. According what I have read in the internet, a good XLR plug is a better connector than a standard TRS. I have a Grado HP-2 recabled with Moon Silver Dragon...

Hi, Regarding the use of 4-pin XLR plugs and sockets instead of the TRS, the designer of my headphone amp (WNA) and others prefer the XLR always, because according to them it sounds a little better, even in not fully balanced amps. My amplifier is a two-channel single-ended (left and...

Thank you for your suggestions. I think I'm going to use a 5-pin XLR male plug in the headphone cable and a matching latching female panel socket in the amp frontplate. Why 5-pin? Because perhaps I'll use a shielded cable and thus pin1=L signal out, pin2= L ground, pin3=shield, for...

Hi I have a doubt about the virtues of the "balanced" connection for headphones (separate ground for each channel and not the usual tip-ring-sleeve jack). If the amplifier is only "semi-dual mono", with the power tranformer shared between both channels (all the rest is dual: there are two...

Quote: Originally Posted by tomb I am a complete noob on this subject, but I recently purchased a cheap meter just so I could get HFE testing. Steinchen's site for Diamond Buffers on the Millett Hybrid specifically describe cheap meter HFE testing for transistors. So, I think for some...

Hi I’ve used the same Modified Linkwitz crossfeed circuit, built using the PCB Tangent sells (with the rotary switch option between high and low crossfeed settings). However, it dulled too much the sound and in some recordings the soundstage was pushed back too much. I thought the crossfeed...

Hi I’ve searched this forum regarding BJT hFE matching and I’m a little confused. There are head-fiers that favour Vbe measurement (which I don’t know how to make) over simple hFE testing. Others say the hFE exact value is less important than the relative values between pnp, npn and npn-pnp...

Hi Yesterday I've installed in my WNA MkII the modified AD744 op-amp, with the output stage bypassed (output taken from pin 5, not 6). The mod is very easy: solder in a 8-pin DIL socket a bridge between pins 5 and 6 and bend slightly the pin 6 of op-amp to avoid any contact with the socket...

Hi all Head-Fiers and happy new year. It's nice to see this forum re-energized by FritzS and Mike... Perhaps these quiet weeks we all have been listening to our WNA, simply enjoying our favorite music, but always it's possible to upgrade... or not: I've listening to the Linkwitz modified...

Quote: Originally Posted by PinkFloyd Hi Jose, The thump is perfectly normal and will not damage your headphones, don't worry! You'll notice the amp thumps with most opamps but is most noticeable with the 8065, I asked David about this and he said it was ok... can't remember the...

Quote: Originally Posted by FritzS Have you test AD8065 vs AD843 vs LM6171 vs SA5534/SE5534? With caps - you use Black Gates (1000uF/25V Nx bipolar type) are in C4 position? Bypassed? The other electrolytic-caps are from/types? Hi Fritz I've tested only AD8610, AD8065...

Quote: Originally Posted by FritzS Jose please can you post the images again - I cannot open it. Hi, Fritz I'm sorry, but I can't post the pictures again because the system doesn't allow to post attachments that they are already in the thread. However, I (and others) have no...

Hi, head-fiers I have some comments about the AD8065 op-amp used as IC1 in WNA mkII headphone amplifier (the IC in the rail splitter is a LM6171). I’ve modify my amp with new wiring to make it very easy to change from the standard cap-coupled output to a direct output (see pictures)and I’ve...

Hi, head-fiers. Thank you very much for the info, Mike. However, when I registered in Rapid to order from them, I've seen that the minimum order for outside UK mainland shippings is GBP 500 (!!) I can't believe it. It's a huge amount that it is impossible to reach for an average DIY...

Hi, 1Up, The red Black Gates (1000uF/25V Nx bipolar type) are in C4 position, the DC-blocking cap in series with the output, hence its great influence in the final sound of WNA amp. As you can see in the picture, I had to solder the IC bypass small cap C2 in PCB underside to make room for C4...

Hi head-fiers, Regarding the input and output caps, I believe that they are the limiting factor in the WNA hp amp. When I removed input caps the sound improved vastly, but I had to use output caps because the bad dc-offset behaviour of the LM6171. I was sure that the sound quality of Black...