By G. Randy Slone
FIRST the excellent news: within the first few chapters Slone has a few solid reviews approximately many principles promoted by means of high-end audiophile "subjectivists". He exposes many rules as myths with out foundation in truth. if you are somebody who spent greater than $20 on your speaker cables, arrange to be indignant. He additionally does a good task of overlaying the fundamentals of amplifiers, the $64000 specifications, etc.
RE-HASH of alternative BOOKS? the 2 different immense authors in this subject are Douglas Self and John Linsley Hood. either have written a number of books and articles. Slone's e-book is more moderen than the sooner variations from either Self and Hood. in lots of methods, Slone turns out to borrow seriously from the opposite authors.
OUTDATED: just like the books by way of Self and Hood, a lot of Slone's ebook is dedicated to chasing distortion out of the enter and intermediate phases of an amplifier. Slone is happy with his enter and voltage amp circuit designs touting them as "unbeatable". this type of daring declare was once questionable in 1999 whilst he wrote the publication and at the present time you should purchase the nationwide LM4702 for $8 and it fits or even outperforms Slone's most sensible designs. The LM4702 is mainly DIY pleasant saving loads of paintings, grief, checking out and components expense. The LM4702 will supply a greater outcome than such a lot any DIY attempt with discrete elements. So it makes seventy five% of Slone's e-book a lesson in historical past instead of tips on how to construct a superb amp.
NO type D: Slone's e-book is dated in different components besides. He states that category D amplifiers usually are not achievable for audiophile use and possibly by no means may be. That arguably wasn't actual in 1999, and definitely is not precise this day. a number of category D items, just like the ICE and BASH modules, were generally praised by means of even the golden-eared audiophiles and are exhibiting up in a few very high-end designs. they're trustworthy, degree good and sound nice yet Slone wrongly dismisses the full class.
CONFUSING: Slone makes use of bizarre abbreviations during the booklet nearly as though he is attempting simply to be various from Self and Hood. the end result merely makes for confusion. for instance he calls the output degree "OPS" and the voltage amplifier degree "VA stage". Self and Hood, for instance, use the even more universal time period "VAS".
ARGUABLY mistaken: Slone states many stuff as truth, with out delivering any references, blind listening assessments, or perhaps occasionally any try information in any respect, to again up his daring claims. for instance, he strongly states taking out the DC blocking off enter capacitor is silly and a truly undesirable thought. but, nationwide Semiconductor of their blind checking out concluded: "In listening assessments at National's sound room comparing various circuit parts utilized in the LM4702 demo amplifier, there has been one half whose destructive impact on audible sign caliber used to be indisputable. A DC blockading capacitor at the enter of the LM4702 degraded sound caliber" (National App notice AN-1490).
NOT FOR newcomers: Slone's publication does not stroll you thru construction even one in every of his designs. a few substantial issues are lacking. Nowhere, for instance, does he offer a components record (bill of fabrics) for any of his designs. plenty of info are lacking like resistor strength scores, capacitor kinds and voltages, and so forth. And the corporate he references promoting circuit forums seems to be out of business.
MOSFET LOVER: Slone is a big fan of lateral MOSFET output units. this is often in direct competition to Self, and almost all advertisement manufactures, who principally forget about them for a few very legitimate purposes. He even is going as far as to boldly write such things as "...all audiophiles might agree that an L-MOSFET OPS layout could be the optimal selection if...". The final arguably winning MOSFET layout used to be the Halfer DH sequence from the early 80's. within the approximately 30 years when you consider that then much has replaced in amplifier expertise yet it sounds as if no longer Slone's dated opinions.
BETTER DIY techniques: if you are eager to construct an excellent DIY amplifier you are with both of the various reliable classification D modules or, if you happen to favor a extra conventional classification A/B layout, the nationwide LM4702 motive force IC. nor is coated in Slone's booklet. nationwide and a few of the category D providers have first-class software notes at no cost and there is plenty of DIY details on the net. nationwide even has an app word for utilizing MOSFETs with the LM4702.
SAVE funds: if you are customarily trying to get a better price, i would put out of your mind DIY thoroughly. not like in Slone's period, a lot has replaced nowadays with the cost of advertisement items losing. i do not believe it truly is attainable to construct an amp that outperforms and prices below an Emotiva or Outlaw until you have already got many of the dear elements laying round. And if $300 for an Emotiva remains to be an excessive amount of pro-sound amps begin round $150 and used amps for even much less. Apples-to-Apples, DIY cannot contact those costs and i would bet an Emotiva will fit or beat whatever in Slone's e-book in a blind listening test.
THEORY: if you are trying to find a e-book that covers idea instead of useful designs, you are far better served by means of the Self or Hood books. both writer does a greater task of masking the technical subject matters in comparison to Slone. Self and Hood largely reference their idea and claims whereas Slone does not.
NOSTALGIA: ultimately, which will construct (or comprehend) an inferior "retro" amp for possibly nostalgic purposes, or a musical device amp, this ebook might help and it truly is more cost-effective than the books from Self or Hood. Slone mentions the various designated wishes of pro/instrument amps and offers a few designs that would be precious. yet for domestic listening there are far better suggestions (see above) which are more uncomplicated, expense much less, and practice greater than his designs.
SUMMARY: retailer your funds and do not purchase this ebook except you are looking for nostalgic and/or musical tool designs.