[bmwpowere36m3]

Looking for a new build, something higher-end and SS... started my journey with a iMod mini, CMOY, SSMH, Gainclone, Mini3, Gamma1 and a SOHAII.

At the time I was using HD580s, which have since been sold and will be replaced with HD600/HD650/HD6xx one of them. I'm also interested in planars, maybe the Sundara.

So I haven't built an OTL or higher-end SS headphone amp. Considering building the latter and I wanted some ideas on what I should pursue, given what I've built and hence something "technically" better.

So thinking of builds based on some perusing:

• O2
• MilletMax
• Whammy
• M3
• Beta22 (2-channel)

I'd like to keep the cost sub $500, though I'd have some room for something exceptional. Please, open to suggestions.

On a tangent, I hear Bottlehead Crack or SEX mentioned a lot for OTL... thoughts?

 

[AudioCats]

Crack is OTL. SEX appears to have output transformers.

Crack can not drive ortho phones well, the output impedance is too high.

 

[bmwpowere36m3]

Crack is OTL. SEX appears to have output transformers.

Crack can not drive ortho phones well, the output impedance is too high.

Thanks for the clarification. I guess my main question is suggestions on a SS amp to pursue.

 

[miketlse]

This looks like an interesting project, but maybe you need to redefine/re-scope it to avoid wasting your manhours/money.

I will be transparent, in that both at work, and in head-fi life, I use the systems engineering approach.

In practice this means: identify your needs>identify your specific performance requirements>identify potential candidate concepts/solutions>downselect to the best solution available.

You are already partway there, but I do have further questions that could possibly refine the feedback from fellow head-fiers.

You mention 'something "technically" better', but 'better' is a comparative term, so you need to clarify the question 'better than what?'
Your bullet point list of builds, are you able to add links to the builds you are investigating? This helps other head-fiers to provide useful feedback.

Sorry if this feedback comes across as being negative.
Your initial questions about suggestions for a SS build are interesting and valid, but if one is going to DIY a SS build the question then becomes why target a 'good enough' build, when a 'best there is conceivable' build, may not take much more effort to identify?
True the 'good enough' build may cost less than the 'best we can collaboratively design' build, but at least this enables head-fiers to choose their priority.

Once again, sorry if my posts comes across as negative, but I just want to try and energise your initial post, into revealing 'what is the best solution that we can achieve in 2021'.

 

[kartk]

There are few good DIY amps available without spending a lot..
Sapphire
Whammy
ACP+
ACA ( a speaker amp but 5W/ch and with resistor ladder can be made to work with HPs)

 

[miketlse]

There are few good DIY amps available without spending a lot..
Sapphire
Whammy
ACP+
ACA ( a speaker amp but 5W/ch and with resistor ladder can be made to work with HPs)

Thanks, but why not add the link to the web pages?

 

[kartk]

ACP+: https://www.diyaudio.com/forums/pass-labs/344836-amp-camp-pre-headphone-amp-acp.html
Sapphire v4: http://phonoclone.com/diy-sap4.html
ACA: https://www.diyaudio.com/forums/pass-labs/215392-amp-camp-amp-aca.html

 

[bmwpowere36m3]

This looks like an interesting project, but maybe you need to redefine/re-scope it to avoid wasting your manhours/money.

I will be transparent, in that both at work, and in head-fi life, I use the systems engineering approach.

In practice this means: identify your needs>identify your specific performance requirements>identify potential candidate concepts/solutions>downselect to the best solution available.

You are already partway there, but I do have further questions that could possibly refine the feedback from fellow head-fiers.

You mention 'something "technically" better', but 'better' is a comparative term, so you need to clarify the question 'better than what?'
Your bullet point list of builds, are you able to add links to the builds you are investigating? This helps other head-fiers to provide useful feedback.

Sorry if this feedback comes across as being negative.
Your initial questions about suggestions for a SS build are interesting and valid, but if one is going to DIY a SS build the question then becomes why target a 'good enough' build, when a 'best there is conceivable' build, may not take much more effort to identify?
True the 'good enough' build may cost less than the 'best we can collaboratively design' build, but at least this enables head-fiers to choose their priority.

Once again, sorry if my posts comes across as negative, but I just want to try and energise your initial post, into revealing 'what is the best solution that we can achieve in 2021'.

I like to DIY, back then you could build an amp for less than a commercial equivalent. Besides the ability to change things yourself and the satisfaction of building something. Nowadays, browsing this forum, diyAudio and Reddit I'm mostly seeing references to off the shelf, CI-FI stuff. Whether that's because the quality is much improved, along with cost AND/OR less desire to DIY.

So do any of these DIY products still compete? Given what amps I've built, is there something new and technically better*. Specifically a SS amp, which ATM I only have a Mini3... I sure there better amps out there. I don't have hard, engineering requirements, like I do at work. User experience and opinion is what I'm looking for.

Budget, like I said <$500.

 

[bmwpowere36m3]

There are few good DIY amps available without spending a lot..
Sapphire
Whammy
ACP+
ACA ( a speaker amp but 5W/ch and with resistor ladder can be made to work with HPs)

Thanks

• O2 - I'm thinking this isn't really a step up from what I have
• MilletMax - already have a few Millet products
• Whammy - Nelson Pass, his "personal" headphone amp design
• M3 - AMB was highly regarded in the day, natural evolution from Mini3
• Beta22 (2-channel) - same as above, just another evolution and $$
• Sapphire - don't know much about it, seen it on diyAudio
• ACP+ - Nelson Pass design, from amp camp event
• ACA - Nelson Pass design, from amp camp event

I guess what differentiates some of them is usage of op-amps and the ability to "roll" them to suit your listening desires. Other's are pure discrete... good, bad, exercise technical design difficulty (who's slide rule is bigger) but are they "better". Mosfets on the outputs, DC coupling or combinations of the above.

 

[kartk]

I have built sapphire, whammy from above list. Actually built multiple sapphire units, many preferred it over some kilobuck SS amps. Its not a beginner's build as you will need to match transistors, setup bias to avoid DC offset, but its quite a rewarding amp. There are few reviews on other site which cant be named.

 

[kartk]

ACP+ is another unique amp where design focus is to provide that rich sound with 2nd harmonics, since its coming from FirstWatt, documentation is really good.

 

[bmwpowere36m3]

I have built sapphire, whammy from above list. Actually built multiple sapphire units, many preferred it over some kilobuck SS amps. Its not a beginner's build as you will need to match transistors, setup bias to avoid DC offset, but its quite a rewarding amp. There are few reviews on other site which cant be named.

Did you build the latest Sapphire (discrete) or the earlier with op-amp? Looking the latest build spreadsheet, it notes matching is not necessary but does help. Biasing with a trimmer is no problem, but I see drift is noted. Whereas the Whammy, I believe, is self-biasing.

Can you describe your take on the Whammy, ACP+ and Sapphire? Likes/Dislikes?

 

[kartk]

I built latest version i.e. v4.x, matching is not necessary but I did found DC offset to be high when HFE values for Q1/Q2 were quite far apart. You can directly buy the PCB and kit from Richard via his site. That would be easier than buying 100s of transistors and matching them.
I havent tried ACP+ myself, but whammy was quite easy to build but it was not as resolving as Sapphire and there was roll-off on either ends of FR. Sapphire in comparison sounded more transparent and retained that bass slam. One advantage of Whammy is opamp rolling and one can change its tonality by swapping opamps in VAS stage..

 

[bmwpowere36m3]

I built latest version i.e. v4.x, matching is not necessary but I did found DC offset to be high when HFE values for Q1/Q2 were quite far apart. You can directly buy the PCB and kit from Richard via his site. That would be easier than buying 100s of transistors and matching them.
I havent tried ACP+ myself, but whammy was quite easy to build but it was not as resolving as Sapphire and there was roll-off on either ends of FR. Sapphire in comparison sounded more transparent and retained that bass slam. One advantage of Whammy is opamp rolling and one can change its tonality by swapping opamps in VAS stage..

Is that the route you took, kit? Did you go open or closed loop? Standard bias?

I think this and Whammy are in the running...

 

[kartk]

Is that the route you took, kit? Did you go open or closed loop? Standard bias?

I think this and Whammy are in the running...

I built it from scratch as in get PCB done locally and match all the parts myself, it was faster than importing the kit. Between open and closed loop I found open loop better with 15dB gain, standard bias setting.