catman Posted August 17, 2014 Posted August 17, 2014 (edited) G'day all, if I've learned nothing else from my humble DIY efforts, it is the great importance of component value 'matching' in things like stereo phono preamplifiers between the two channels and the like. It really makes a difference! At the very least in my opinion any DIYer should possess a good multimeter and capacitance meter, and especially the latter! The one percent metal film resistors I routinely use can generally be relied upon for value accuracy, but capacitors are a totally different story! Even WIMA polypropylene capacitors of the same 'marked' value are often somewhat off tolerance in value when actually measured! These days I spend the time to find matched value sets, and whilst it can be time consuming, it is definitely worthwhile! This is possibly why even my simple one op amp phono stages seem to possess superb stereo imaging. Yes it really makes a difference! Regards, Felix. Edited August 17, 2014 by catman 1
Zaphod Beeblebrox Posted August 17, 2014 Posted August 17, 2014 This has never been a mystery to well-established companies like Krell, Mark Levinson, Gryphon or ME. All those companies have very closely matched components in critical areas.
Addicted to music Posted August 17, 2014 Posted August 17, 2014 My pet hate is dual gang analog volume pots... 2
TMM Posted August 17, 2014 Posted August 17, 2014 My pet hate is dual gang analog volume pots...100 times this. I only bother matching components in speaker crossovers and in-band filters (e.g. bass/treble boost, an equaliser). The large majority of capacitors in equipment aren't so value critical. 1
catman Posted August 17, 2014 Author Posted August 17, 2014 G'day all, I think an application like a DIY phono stage 'is' important as that is a front end component source and any deficiency here cannot be rectified elsewhere. Having an otherwise very good phono cartridge like my OEM stylus Shure M97xE, but with slightly ordinary channel separation performance makes good stereo performance in the phono stage especially important, in my opinion. Regards, Felix. 1
Zaphod Beeblebrox Posted August 18, 2014 Posted August 18, 2014 My pet hate is dual gang analog volume pots... Indeed. Given the exceptional matching of the elements of the Alps 'Blue Velvet' volume pot, such things seem to be needlessly tiresome. 1
valvedude Posted September 29, 2014 Posted September 29, 2014 My pet hate is dual gang analog volume pots... why
valvedude Posted September 29, 2014 Posted September 29, 2014 (edited) G'day all, if I've learned nothing else from my humble DIY efforts, it is the great importance of component value 'matching' in things like stereo phono preamplifiers between the two channels and the like. It really makes a difference! At the very least in my opinion any DIYer should possess a good multimeter and capacitance meter, and especially the latter! The one percent metal film resistors I routinely use can generally be relied upon for value accuracy, but capacitors are a totally different story! Even WIMA polypropylene capacitors of the same 'marked' value are often somewhat off tolerance in value when actually measured! These days I spend the time to find matched value sets, and whilst it can be time consuming, it is definitely worthwhile! This is possibly why even my simple one op amp phono stages seem to possess superb stereo imaging. Yes it really makes a difference! Regards, Felix. hi if you use good quality condensers and check with an ESR meter you will be OK if you are on a budget i find the EXR condensers from WES components are good valve i would all so look at using 1% value resistors were possible EG in the differential drive stage buying transistors and matching the outputs is the more crucial thing to be doing if the circuit is a well designed circuit in the first place the harmonic distortion and symmetry on the positive peak and the negative peak of the output will be pretty much even i repair amps all day every day domestic professional 24/7 i use this approach and have no problems Edited September 29, 2014 by valvedude
valvedude Posted September 29, 2014 Posted September 29, 2014 (edited) Indeed. Given the exceptional matching of the elements of the Alps 'Blue Velvet' volume pot, such things seem to be needlessly tiresome. i buy mine from Alps 'Blue Velvet' from Germany and have measured them and have not found a difference to jump up and down about lol what you think Edited September 29, 2014 by valvedude
valvedude Posted September 29, 2014 Posted September 29, 2014 G'day all, I think an application like a DIY phono stage 'is' important as that is a front end component source and any deficiency here cannot be rectified elsewhere. Having an otherwise very good phono cartridge like my OEM stylus Shure M97xE, but with slightly ordinary channel separation performance makes good stereo performance in the phono stage especially important, in my opinion. Regards, Felix. ditto
andyr Posted September 29, 2014 Posted September 29, 2014 i buy mine from Alps 'Blue Velvet' from Germany and have measured them and have not found a difference to jump up and down about lol what you think The 'non plus ultra' of volume pots IMO is the TKD stepped attenuator - with the Bob Crump mod (as used in the cost-no-object Bob Crump/John Curl 'Blowtorch'). Regards, Andy
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