I have just completed my PPAv2 and STEPS boards and am getting around to the casing. I have an expensive filtered IEC inlet socket lying around and was planning on using this to feed the STEPS. Is this overkill or just plain unwise since I understand the STEPS features filters also? If it...

I have had an order with Mouser on hold now for 2 weeks all because of one lousy part. I've had enough of waiting and want to find an available replacement part for Q31-33, buffer driver transistor 2N5088 (Mouser ID: 512-2N5088_J61Z). I would preferably like a part equal or better in...

Hi everyone, Its been about 4 years since I've last posted on this forum and its great to catch up with the posts and the latest happening in the DIY community. Right, bite the bullet time. I've just recently purchased a pair of HD650s and want to build a new amp especially for them. I...

After having completed a Regulated LM317 PS based on a torroidial tranny, I've discovered that the tranny is emitting noise that can be picked up on my amp. Although the amp and the PS are in seperate enclusures, I stack them one on top of the other to save space. The noise is certainly from the...

I'm sure this one has been done to death but a search didnt prove helpful due to the vast number of different PS's out there. I'm looking to build a simple, mains, IEC type input, supply to power my buffered CMOY. I only require a single supply since I am using a buffer in a seperate...

Anyone?! I've measured offset on my amp which is 0.9mV and 1.4mV for each channel. The offset on my source is 0.6mV per channel. Should I be worried considering I omitted an input cap on my DIY amp? Cheers!

OK now this has just completely spooked me out seeing as I've only had my D-EJ1000 a week or so. But today I noticed that if I hook my headphones up through the remote and put the volume to zero WHILE A CD IS PLAYING, I get some weird whirling noise ONLY in the left earphone. But, this sound is...

Having purchased a portable Sony cd player (ej1000), I have found that the quality of the line out far exceeds the quality of the headphone out. Now I've tried powering headphones directly from the lineout and the quality I get is amazing, however I understand that this is not advisable due to a...

Hey guys, Just built a new amp - its a buffered CMOY using 1 OPA637 and 1 EL2001 per channel with a BUF634 in the power supply. I'm using 2200uF rail capacitance and have decoupled all PS pins with a 0.1uF Ceramic bypassed with a 100uF Electrolytic. I'm using a 24V ac-dc wallwart supply to...

Hey Guys, When building a BUF634 power supply for use in a CMoy amp is it best to place the BUF after the bypass capacitors in the power supply or before them? Or does it really make no difference? Edit: With regard to decoupling power supply pins at Op Amps, should i also decouple the...

OK so who else has seen those Grados around her neck in Alicia Keys video! Man, I nearly pissed myself!LOL

Hey Guys, I've been trying to figure this problem out for several days now but seem no closer to solving it. However, I have carefully observed its effects. Some of the following may sound incredibly tedious so I hope I explain it all nice and simple! Firstly I'll explain the amp I've...

Hey Guys, I've just been testing a DIY CMoy+Buffer amp I'd made a while ago now, only got round to it after getting back from university. When driving grados the amp can drive them to incredible levels, I mean 11 'o'clock is the maximum I'd like to go before I start worrying about damaging...

Hey Guys Just finished building a new CMoy amp with buffered outputs. I'm powering the amp off of a regulated mains adaptor which is dishing out 24DC at 300mA. I'd been testing the amp for a while and everything was running sweet until eventually an annoying loud hum kicked in! I'd...

Hey Guys, I'm building a new beefed up CMoy with loadsa modifications. It's a OPA637 with two BUF634 per channel. I was debating whether to use a single or double buffers per channel??? Any suggestions?? Would there be an audible difference and would there be any advantage in using two OPA637s...