Seeking design input/advice for a complete system overhaul

[Mr Noisy]

Hi everyone,

(new member warning - mods please move this thread if it's in the wrong place)

Now that I'm nearly finished building my Statement II's, my current receiver (Marantz NR1501 @7x50W) is too underpowered to drive them. Building these speakers (incl. designing/stuffing my own crossover PCBs) has been fun and I want to keep going with the DIY to solve this problem. I'm hoping to get your input/help with a hifi system design I've been working on. I'll add my specific design questions up front in case of TL;DR, or you don't need the rest of the info to respond. I've tried to research as much as I can first, so hopefully this isn't too frustrating for the experts out there!

Please see the attached diagrams (existing current state vs. planned future state systems). Assume that any existing system components that I've left in the future state diagram (i.e. the greyed out parts) are kind of a done deal for now - unless you see any real clangers in there!





DESIGN QUESTIONS

1. Is it proper to have the headphone amp go through the buffer?
2. What does this mean re. having two attenuators in the circuit? (one on buffer, one on headphone amp)
3. WHAMMY or ACP+ for the headphone amp? This question is not about which is better, but which is easier to build - I'll probably end up building both anyway...
4. You'll see that I've spec'd XLR balanced interconnects where available. Aside from the*argument against introducing unnecessary complications to the system, I figure that if they're already there then why not use them?* Or is there another argument against them?
5. Noting the above, what interconnect would you recommend between the buffer and the headphone amp? Unbalanced RCA or balanced XLR?
6. Is there any advantage to balancing the monoblock--> speaker connections? The research I've done says no, but I'd like your thoughts. Either way, I'll use SoundOns for this job.
7. I understand that the WHAMMY and the ACP+ headphone amps can be configured as pre-amps. This is probably a dumb question, but could I use one of them to drive the monoblocks while I build the DCB1 buffer? Or is that asking too much of them? The answer to this question will drive the build order more than anything else.

DESIGN GOALS
The system I'm building must:

• Have good (high?) fidelity, in the true sense of the word
• Have good WAF :-)
• Maximise the DIY side of things - fearless!
• Utilise 'tried and true' rather than 'bleeding edge' solutions. I'm handy with a soldering*iron, but don't know enough*to design*my own hifi components (so, almost fearless...)
• Help me avoid 'upgrade-itis', although I understand that's hard with this hobby :-)
• Be built in the right order - the goal is to get the Minimum Viable Product (MVP) going in order to get hifi sound into my ears, before starting on the next logical component in the system
• Steer away from the 'snake oil' aspects of hifi system design

DESIGN COMMENTS

• I chose the Topping D90 over the RME ADI-2 for my DAC, as I understand that only the D90 can have its pre-amp function bypassed through the setup options. I could be swayed back toward the ADI-2 if someone else knows something that I don't...
• The DAC will likely be the last component I add to the system. This will allow me to see if I can build up the courage to build my own DAC before I get to it.
• Spotify + Chromecast = good WAF. It's not intended for hifi listening, but will get me started for digital sources anyhow.
• The research I've done suggests that the best listening improvements are typically made at the source and at the output, with everything in between being kind of secondary. That's why I built the Statement II's first, even if they'll be underdriven by my existing receiver, and why there's a raft of upgrades already planned for my TT. I'll probably talk about that in another thread. This thread is about pretty much everything else...
• ...except room treatment.I know that this is important too, but I need to do more research before asking dumb questions about it (again, likely in another thread)

Well, thanks for reading - I look forward to hearing your thoughts on my ideas.

Mr Noisy

[technodanvan]

Hi Mr Noisy!

My thoughts, for what they're worth...

1. While perhaps not 'proper', having the headphone amp placed after the buffer shouldn't hurt anything.
2. Having two attenuators just means you'll need to make a decision on which one you'll use. I think easiest (and safest) would be to run the headphone amp volume maxed out and actually control volume via the buffer.
3. I'm no help here (sorry)
4. Using balanced connections is fine, certainly won't hurt anything.
5. Personally, I don't think it would make much difference unless you have a very long run, in which case the balanced connection would be superior.
6. Not in my opinion.
7. I can't really answer that.

Other thoughts:
Have you considered using NCore or Purifi amplifier modules instead of the honey badger design? You'd have more power and smaller, cooler running equipment. It's somewhat less DIY though (the modules come assembled) and probably more expensive. This may help with the upgrade-itis though.

Why not just use the DAC as the preamp and volume control? In fact, I would argue the buffer isn't going to 'add' anything useful to the signal path, and using your DAC as a preamp has worked well for lots of people. I understand the desire to build stuff, of course.

Don't discount the convenience of a remote control! As specced, you'd need to set your volume before sitting down.

[Mr Noisy]

Other thoughts:
Have you considered using NCore or Purifi amplifier modules instead of the honey badger design? You'd have more power and smaller, cooler running equipment. It's somewhat less DIY though (the modules come assembled) and probably more expensive. This may help with the upgrade-itis though.

Why not just use the DAC as the preamp and volume control? In fact, I would argue the buffer isn't going to 'add' anything useful to the signal path, and using your DAC as a preamp has worked well for lots of people. I understand the desire to build stuff, of course.

Don't discount the convenience of a remote control! As specced, you'd need to set your volume before sitting down.

Thanks for the input Danny,

That's just the sort of sage advice I was looking for. I'll look into the NCore and Purifi modules this weekend, and a DAC as preamp too. I didn't realise you could feed an analogue input through the DAC as well.

I'm not going to die in a ditch over whether something is DIY or not - besides the Honey Badgers being DIY, I was looking at them because 1) I understand that they can drive my Statement II's and 2) They seem to be pretty good bang for my bucks in terms of SQ.

Cheers mate

[1Michael]

My first turntable bought in 74 was the SL 1200 with a Quad cartridge. I don't know why Quad never caught on.

[technodanvan]

I didn't realise you could feed an analogue input through the DAC as well.

I think that largely depends on the DAC. Mine is from NAD and has a phono input on it, but that is certainly the exception.

[Mr Noisy]

Mine is from NAD and has a phono input on it, but that is certainly the exception.

That sounds ideal... can I get the model # of your DAC please?

[technodanvan]

That sounds ideal... can I get the model # of your DAC please?

I have the NAD M12, which is more than just a DAC really but supposedly features the same DAC as the NAD M51. It can be had for much less than retail on auction sites, though you don't get a warranty that way. I want to say other NAD models come similarly equipped that may be more cost effective, but none of them are just a straight DAC.

[Mr Noisy]

I want to say other NAD models come similarly equipped that may be more cost effective, but none of them are just a straight DAC.

Thanks again Danny for giving me this alternative option. I'm now looking at either the NAD C 658 or miniDSP SHD to substitute for the DAC and buffer in my original plan. And the purifi-based monoblocks from March Audio look really good too!

Cheers

[technodanvan]

I've seen good things about the C 658, I don't know if ASR has reviewed it or not but I'm sure the internal DAC is competent. The March Audio amps are really enticing! Had I found those prior to purchasing my NAD M22 v2 (an ncore design) I think I might have gone that very same route.

Glad I could help give an alt option! It's certainly more costly but perhaps more user friendly and adaptable to future inputs/needs. Note too the C 658 can handle add-on cards as well, so if you needed HDMI for example, you could add that feature. The cards are overpriced in my opinion, but it beats buying a whole new stereo. Oh, and if BluOS works the same way as it does on the M12, it'll allow the NAD to be a Roon endpoint.