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We were thinking that we had seen this Italian tube amplifier before, and indeed we had. And we don’t mean one like it, but this very one. It’s a demo model. It’s been to Vegas at least three times, and we’ve seen it perhaps twice more. Sometimes it was playing, sometimes not. It would be understandable if it looked a little tired, though in fact, but for one of its tubes, it looked fresh and rested. The output tubes — since we’re on the subject — are 845 triodes. The 845 has been around forever. RCA developed it in 1931 as a driver for its AM radio transmitters. Like other tubes designed for transmitters, it can operate at much higher voltages than the usual KT88 and other 6L6 variants common in modern audio amplifiers, but its bayonet mount betrays its age. The tube is oriented in its socket by a tiny nub that fits into a slot. If the nub breaks off you can easily insert the tube the wrong way around. That 38 ULTRA HIGH FIDELITY Magazine Listening Room Mastersound Evolution 845 had clearly happened with one of the tubes in our amplifier, and a blackened patch on the circuit board was silent witness to what had happened. We replaced the tube, and the amplifier seemed none the worse for the experience. On the rear panel are recessed controls for setting up bias of the tubes. This is to be done by “qualified personnel,” according to Mastersound, but the owner’s manual gives no hint as to how this is to be done. Oddly, Mastersound refers to the bias settings as “semiautomatic.” We ignored them. You might assume that the 845 tubes are arranged in the usual push-pull configuration, but they’re not. This is a single-ended amp, with the two output tubes (on each channel) operating in parallel. Why? Single-ended amplifiers suffer from relatively high even-order harmonic distortion, but they are exceptionally linear at very low output. They go “class A” amplifiers one better. Inverse feedback can be used to reduce harmonic distortion on an amplifier, but the Mastersound eschews that as well. Now perhaps the configuration calls for a bit of explanation. The usual way of configuring a power amplifier, either tube or solid state, is with a pair of complementary output devices, one for the positive half of the wave, one for the negative half. That allows partial cancellation of harmonic distortion (actually the even harmonics, though not the more disturbing and unmusical odd harmonics). On the other hand, the wave can be asymmetrical if the two devices aren’t rigorously identical, and there can be a discontinuity at the zero point, where one device takes over from the other. In a single-ended amplifier, a single device or group of devices does all the work, and there can therefore be neither discontinuity nor asymmetry. The Evolution 845’s styling is identifiably Italian, which is far from being a criticism. The amplifier is solid, and it is heavy, which inspires confidence. It is wider than many equipment racks. However its most noticeable styling device is also its most problematic: the multileafed metallic structure that protects the output tubes physically and helps dissipate the considerable heat generated. Tap the structure and it rings like the bells of St. Mary’s. If this amplifier were ours, and assuming we didn’t own a cat, we would probably remove it. The front panel is a simple one, with an input selector and the volume control. There are four inputs, one of them identified as “tape” (the term seems quaint nowadays), but it is not part of a tape loop. Another input is labelled “direct,” which means it bypasses the volume control. That would be useful for the main channels of a home cinema system. A two-button remote control made from the same wood as the chassis sides allows adjustment of volume. Though the Mastersound 845 had been to a lot of shows and had presumably had plenty of run-in time, it also had one new tube, and so we gave it something like 100 hours more before getting down to serious listening. Although our
equipment stands are wider than most, we elected to operate the Mastersound on the floor, sitting on its built-in cones. That’s because we remember years ago reviewing another large tube amplifier, the Audiomat Opéra (UHF No. 69), and finding its bottom end a little lean. Placing it on the floor had made everything right again. Incidentally, our Moon W-8 reference amplifier also sits on cones, and we also have it on our hardwood floor. We decided to make this an allanalog session, and so we ran our Atlas Mavros cables directly from our phono preamplifier to the Mastersound. The amplifier has output posts for both 4 ohm and 8 ohm speakers. Our Reference 3a Supremas have a 4 ohm impedance, but we know from experience that the 8 ohm output often sounds better, because the 8 ohm transformer winding has less wire. We thought that, if the amplifier didn’t seem to have enough muscle, we could always switch to the 4 ohm tap. It never happened. The rest of this review of the Mastersound amplifier can be found in the complete print or electronic version of UHF No. 92. Order the print issue from www.uhfmag.com/IndividualIssue.html (it’s case sensitive). Or subscribe at www. uhfmag.com/Subscription.html. The electronic issue is available from Maggie at www.uhfmag.com/maggie.html. We now continue in imitation Latin. Re facin henis nisl iustrud enim aute duis dignisc iliscipissi. Tum veliquat ulpute dolore volore facipsum esequat. Ut lan veliquat praese facilit lutpat nibh euguero ea feuguer suscing enismod dolorero odiamco rtiscil lamconsequat wismod modion vel ulputat. Utpation utpat augait am, core tisi. An hendreet nonsenim dit, ver sustrud dunt utet autem quam, sis augue magniam consequat adipis adiam, consed te ming esent loborper iure commodio commodit lum zzriure vullumsan henim iustin utatum vel ilis aut loborperilla feum do odolore commodolore dolore dolesto eu feu feu feuipsu scipit ad molorem ex ero odolobore dolobortie digna conullaor si bla consecte et exerit lum alismolore ming esent vullamc onullan henisl ute core vent volor si. Sumsandre con hent ilit nim nis accum nissequam ero eraestrud dolore ese dolore dolutat, volobore diat praestismod te facilla facil inci blan et aliquis ciliquiscil dignis am quis niamet nisse eniamet, sis nibh eraesen dionum zzrilla feuipis modolut adip euis dolessi. Iquametuerat nullamc ommolore con utatuer ostinit nos eugiam nos adionsed euisi ex eril ilismod te te mod et adionse quissent aliquisi te doluptat ing enit ea alis accumsan velessectem dolorpe rostrud dipis nonsenisi. Iril iure molobor sustismod molore mincilit acing er accum vulput in utat, quat ad eril doloreet lan euismol ortinim digna autpat lobor sectetum quamconulla commy niation sequatie el ip ea augait, consequam adionsectet alis ex exer sum zzriure eugiam iriurerit ad eros dit alit num del ullutpat, sisisl et et volorper si blam, quatem init, con- THIS MAGAZINE IS INTERACTIVE! sequi bla coreet, vent iriusci bla feu feuipis modolore dolesse conulla feuis adit laor ilit lutpatin el in velisci ncilla facinibh eugait adipit nibh et nis nonsed magna feummod do coreros eugait il ex eugait wisi ex et num quisim aut atum del del dolobore eros endigniatue dolor secte ex eugiat. Illa corperostrud tisi. Rud doloreet wis alit ut lum in heniscidunt aut ing et lorper sequis non ut ilit lore facilis sequat. Duis ad dolor adiam quatiscidunt praestie er ametummod tat. Agna feuipisl essequis accum in utat. Andigna feuguer sustrud dolore conum ex et enisit prat vulputat iure dunt verit lutpat nullam velesto commolortie dolorpe riurem zzrit, senit nonsequis nibh er sum nim aliquis at accumsa ndrercipsum vent nullam, venis nim ipisim irit num euisis nisl ing elit wis adionullamet praestrud tie consequatue faccum autet, quis aliquat irilismolore exerat acidunt dolesto ex er incilis essim numsandrem verosto eummy nim velendre er ing euis nonulla faccumm olortionulla feuipsum eu facipis cipit, volobore erillaor in utpatie vel iustisl dipisim zzrillutetue corpera esendit ipisi blandrer susci te magna feugait vel ut iniam, velis amcore facilisl erit venit augait lute tem ing ercilit, velisci liquatuer il utatue consequat. Cil et veraessisl utat, sed tio dionsendipit nit aliquisi eu facincidunt lobor iure do ero dignit ullaortion ute feugiat. It work in three ways. Summing In the table it up… of contents, click on an article title, and you are whisked right to the article. Model: Mastersound In the list Evolution of advertisers 845 on the second-last page, Price: $15,000 click on an ad name, and go right to the ad itself. Sizet (WDH): 55 x 45 x 27 Then cm, click on an ad, Inputs: and your Three browser high-level, will one take direct you right to the advertiser’s Web page. Rated power: Remember 55 watts/channel when you’d have to circle little numbers Most liked: Outstanding on a card sound you would then mail in? Least liked: Heat Doesn’t diffuser that rings seem like like a a Lorem long time eum ago? iurer iure tatue modigna bell, no recording or preamp output feugait eros nisl utatum ip el ex eu feui Verdict: Forget power ratings, this eu facipsusto ea faccums andignis dit amplifier can handle pretty much illaore do odit ilis dipit do euis eui te anything feugait niamcom modolor perilluptat. To commy nim iustio duipis num nos- ULTRA HIGH FIDELITY Magazine 39 Listening Room
Page 1 and 2: No. 92 CAN $6.49 / US $7.69 USB DON
Page 3 and 4: Issue No. 92 Cover story: It’s be
Page 5 and 6: THE ONLY GOOD DOG EARS ARE… …no
Page 7 and 8: A note of thanks for your valuable,
Page 9 and 10: 1) Mac Mini ---> Optical TOSLINK ca
Page 11 and 12: about 147 ohms. I was expecting rou
Page 13 and 14: ucts. And finally if the binding po
Page 15 and 16: et amet lore molobor percipit in en
Page 17 and 18: attend press events, some with free
Page 19 and 20: The rest of this article can be fou
Page 21 and 22: Tum veliquat ulpute dolore volore f
Page 23 and 24: erilla adignim num nim am, commod e
Page 25 and 26: Q. What is a home theatre system? A
Page 27 and 28: ad doluptat. Quat ip eugait wisseni
Page 29 and 30: have to be careful with it. I regul
Page 31 and 32: Kandy K2 “A neat balancing act, c
Page 33 and 34: Reflex speakers, the most common ki
Page 35 and 36: augait iriliquisim velesse quatet a
Page 37: tat, suscips ustrud tie vel dolore
Page 41 and 42: THE ACOUSTIC COLLECTION: This is th
Page 43 and 44: The optical connection Up until now
Page 45 and 46: Get UHF from Maggie on your desktop
Page 47 and 48: using the Atlas Opus (now discontin
Page 49 and 50: Conclusions That we would recommend
Page 51 and 52: as the Mavros, but it’s stuck on
Page 53 and 54: tant, but then they are usually pos
Page 55 and 56: INTERCONNECTS ATLAS HYPER SYMMETRIC
Page 57 and 58: UHF14 POWER BAR Most power bars kno
Page 59 and 60: ed pepper to its music. Felix Hell
Page 61 and 62: We Get Requests (CD) An amazing 196
Page 63 and 64: So you have, or plan to have, a cla
Page 65 and 66: van Swieten. The discovery marked h
Page 67 and 68: in which a multipart popular song w
Page 69 and 70: mentor Gustav Mahler, and others, s
Page 71 and 72: etween the ordinary and the spiritu
Page 73 and 74: songs. Except for the frothy Septem
Page 75 and 76: old friend, and is thus in a positi
Page 77 and 78: Do your friends have bassier speake
Page 79 and 80: eing formed with Hong Kong’s TPV
Page 81 and 82: Working Tools Most of the tools we
Page 83 and 84: Why do UHF readers start reading th

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