Gramophone Dreams #43: First Watt F8 power amplifier

I spent my childhood summers on the Reichert family farm near Turtle Lake, Wisconsin, where, inside the red 1880s barn, my uncle Harold played 78rpm records for his cows.

He used a wind-up Victrola sitting on a shelf directly in front of the cows, just below a framed reproduction of an Alpine landscape painting. He said the music and the mountain scene relaxed the cows, causing them to give better milk. Harold played the same Gustav Mahler symphony every day. I remember how quickly each disc ended, how I had to run over and change it, and how cross he got when I played the discs in the wrong order. I remember how the room smelled like hay and wet cow pies, how half the sound from the Victrola was a scrapey, hissing noise, and how Mahler's (and Harold's) Austro-Bohemian German-ness dominated the room.

These sensuous farm memories entered my mind after watching a movie, Desperate Man Blues, about a notorious radio disc jockey and 78rpm record collector named Joe Bussard, who explains that he found many of his most valuable discs by knocking on the doors of houses without electricity, in one case walking waist-deep through a swamp to get there. Joe Bussard is legend. Watching him in his wood-paneled basement playing rare discs from the 1920s is the purest illustration of what an evolved, music-loving record collector looks like.

Joe wears plaid flannel shirts, drinks beer, and sits in a gray steel office chair at the end of a long wall containing thousands of brown-sleeved, unlabeled, deliberately disorganized 78rpm discs. In front of him are several turntables, including his current favorite, a Technics SP15 with an Audio Technica ATP-12T tonearm. To his side is a 1970s-looking equalizer amp with faders that he plays like a dobro (which he also plays) and a shelf with a row of cassette decks.

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Tucked in a corner at the end of the record wall, at least 25' from his DJ-command post, sits a single, corner-positioned Altec Laguna–looking speaker that is definitely not an Altec. But what is it?

I posted this picture of Joe's blond-wood corner speaker on Facebook, asking my friends if they could identify it. Twenty-five people guessed incorrectly. Then I ran into an article about Joe Bussard by Sound & Vision editor Al Griffin wherein he described the speaker as "furniture-type." Intrigued, I wrote Al, asking if he knew the brand or model. "As you say, Joe Bussard is a highly evolved listener, but not what we would call an audiophile," Al responded. "He didn't care about front-end gear aside from cartridges and needles and couldn't tell me the brandname or model of his speaker. I called it a "furniture-type" speaker because it's likely a DIY creation he picked up at a yard sale."

Joe begins his listening by pulling a disc from the stacks while telling a little story about the artist or where he found the disc. Next, he chooses a cartridge and a stylus, then adjusts the platter's speed, usually ±1–3rpm. As the record begins to play, Joe quickly adjusts the EQ (which he does for every disc). This EQ adjustment is an important moment, because it shows that Joe knows what these records are supposed to sound like, and he knows how to achieve that sound. With speed and EQ set, Joe leans back, closes his eyes, and is gone.

Joe Bussard listens with such practiced, knowledgeable intent that it is easy to see that he has devoted his entire life to listening.

First Watt F8
The first solid-state amp I ever used was a Dynaco Stereo 120, which I thought sounded evil. The second was a homemade, class-A, 20Wpc stereo amp. It sounded a lot better but burst into flames during its second week of life. The third was a Hafler DH-200, which I built as a kit then deluded myself into liking. After that, I auditioned and dreamed of owning (but could not afford) the John Iverson–designed Electro Research A75, the AMP-1 by Andy Rappaport, the Mark Levinson ML-2 designed by John Curl, the Krell KSA-50 designed by Dan D'Agostino, and—last but not least—Pass Labs' first product, the Nelson Pass–designed Aleph 0.

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If I could have any of those dream amps now, it would be the Electro Research A75. And the Pass Labs Aleph 0. Both. I heard an Aleph 3 recently, the Aleph 0's successor. It was causing John DeVore's Orangutan O/96 speakers to sing with sweet, beguiling ease.

Nelson Pass has been designing amplifiers nonstop since cofounding Threshold Audio in 1974. Since then, the sound of a Pass amplifier has evolved to become not just more compelling and definitive but also subtler and more sophisticated—especially his recent, more esoteric designs for First Watt (footnote 1).

Since I started writing for Stereophile, the Pass Labs XA25 and INT-25, as well as the First Watt SIT-3 and J2, have become essential reviewing tools, satisfying both the romantic and engineering sides of my brain while reminding me daily that all my solid-state dream amps operate in pure class-A. When the First Watt F8 was announced (for release in September 2020), I asked Nelson in an email what yet another low-power, class-A JFET amp could possibly add to what I was already getting from the J2, which I reviewed in September 2016. He replied, also by email, "I wanted to create yet another amplifier with the SemiSouth SiC R100 power JFETs, so in 2015 I developed a design with the same output stage but an alternative front-end circuit. As the years went by, I put some more work into it, and now we are finally releasing it as the F8." (In the next two paragraphs, the words are his but the emphasis is mine.)

"The F8 is a stereo, two-stage single-ended class-A amplifier using the [new-old-stock] Toshiba 2SJ74 P channel JFETs and SemiSouth R100 SiC power JFETs for signal gain, plus IRFP240 MOSFET mu-follower current sources, for a total of only three devices per channel.

"The topology is similar to the J2 amplifier but has only one front end transistor instead of six, operated as a current feedback amplifier (CFA), as opposed to the J2's voltage feedback (VFA) differential input. This front end is more consistent with the single-ended approach to amplifier design and yields a purer second-harmonic character, less distortion with 5dB lower negative feedback, greater bandwidth, and higher damping factor." The owner's manual explains the F8 design further, shows measurements, and provides a schematic of the simple circuit. As best I can tell from the manual's distortion-vs-power graphs, at 1% THD the F8 puts out 25Wpc into 8 ohms and maybe 13Wpc into 4 ohms. Input impedance is 100k ohms. Output impedance is 0.2 ohms.

I asked Nelson how readers could tell if the F8 will drive their speakers effectively.

"As the F8 is an extension of the J2, their similarities are helpful here," he replied. "The J2 was always really excellent with efficient speakers (90dB and above) that naturally have good dynamics and an impedance above 8 ohms. Both are happy enough with lower impedances, but they deliver less power below 8 ohms in proportion."

My experience suggests that choosing a speaker with high impedance and a benign phase characteristic is more important than high sensitivity.

Typically, power amplifiers develop 25–30dB of voltage gain. The First Watt J2 makes 20dB. The F8 makes just 15dB, which is unusually low for a production amplifier. Therefore, I do not recommend driving the F8 directly with a volume-controlled DAC. For this review, I used a Rogue RP-7 preamp, which makes a maximum of 14dB of gain single-ended and 20dB in balanced mode. Unlike the J2, which has both balanced (XLR) and single-ended (RCA) inputs, the F8—being an intrinsically single-ended design—has only single-ended inputs. The list price of the F8 is $4000.

Listening with DeVores
My advance plan was to use the easy-to-drive (10 ohm nominal impedance) DeVore Fidelity Orangutan O/93s to compare the F8 to the First Watt J2 and Pass Labs XA25 amplifiers. The plan seemed fair and interesting, as both of the older Pass-designed amplifiers have proven they play well with the DeVores. For some tube-vs-transistor fun, I thought I'd finish off this column by comparing the 25Wpc, single-ended, solid-state F8 to the 22Wpc, single-ended, 845-tubed Line Magnetic LM-518 IA.

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F8 vs J2
I began my comparisons using the J2 to play Carlos Cipa's Correlations (on 11 pianos) (24/44.1 FLAC Warner/ Qobuz). Right away, the J2's rendering of the recording's picturesque tone and hypertextured space made me feel guilty about how long it had been since it had powered the Orangutans.


Footnote 1: Pass Laboratories Inc., 13395 New Airport Rd., Suite G, Auburn, CA 95602. Tel: (530) 878-5350. Web: passlabs.com
ARTICLE CONTENTS

COMMENTS
Zwingli's picture

Mr. Reichert,
It seems to me that in every review of a new amp that comes across your review desk you compare it to the Line Magnetic 518IA. Based on most of these reviews, the LM-518IA holds its own and in many key parameters betters these newer amplifiers. You never tell us of any breakdowns of the LM-518IA even with all of the physical moving you must do with this amp. I never even read of you replacing any of its tubes!
If I were considering buying an integrated or power amp this day I would purchase a second-hand LM518IA and live happily for a long, long time!
Zwingli

Herb Reichert's picture

I've used that built-like-a-tank Line Magnetic LM-518IA since 2014 and pushed and jammed and shoved it about with zero problems. I once dropped an 845 on my wood floor and it did not break. If I remember right, the cathode still fired and the tube lit up, but would not conduct. A new Chinese 845 cost me like $110. Meanwhile, I have installed some NOS RCA 12AX7, 6L6, and 5U4 tubes – just because I collect these tubes.

I hope that helps you.

herb

Jack L's picture

Hi

Good luck with yr new China made 845!

I read enough complaints online against the quality control inconsistency of Chinese made tubes !

Jack L

tonykaz's picture

I sold Mr.Bussard my family's 78s, way back in the day.

A lady music Reviewer for the NYTimes wrote a book about Joe and 78 Collecting.

It seems that there is only a small number of 78 collections, she knew them all. ( she is one herself ).

We have a Joe Bussard in Mr.MF of Stereophile. I can think of only a few 33.3 collectors like Mr.Bussard: Mr. Fremmer, Mr.Michallef, The Jazz Shepherd, perhaps Mr.JA2, the 15,000 Album collection of Mr.HR, the lifetime collection of TTVJ and possibly the Audiophiliac & the Grand Master of all who aspire: Mr. Chad Esq.

I wonder if ALL the above should bow to the French streamer Quobuz?, which would make nearly everyone/everywhere a collector beyond their most extravagent imaginations.

20 Years from now, we will probably have Pass powered Klipsch Cornwalls controlled by an iPad selecting streamed music just like Meridian & Bob Stuart envisioned a couple of decades ago!

All the dots are connecting: Active Klipsch starting at under $1,000 to $10,000+ LaScalla.

The future is NOW!

Tony in Venice

ps. A DAC specialist reviewer would and could be a fascinating and useful field. Could we have a "Wall of Fame" of DACs like Tyll had for headphones? Someone that could make DACs interesting would be one hell of a writer.

Jim Austin's picture
>>I can think of only a few 33.3 collectors like Mr.Bussard: Mr. Fremmer, Mr.Michallef, The Jazz Shepherd, perhaps Mr.JA2, the 15,000 Album collection of Mr.HR, the lifetime collection of TTVJ and possibly the Audiophiliac & the Grand Master of all who aspire: Mr. Chad Esq.<< I regret to say that I do not belong on that list. My collection is quite modest. Jim Austin, Editor Stereophile
tonykaz's picture

I included you as a matter of courtesy since you are now up-top of the Audiophile hierarchy . Of course, I have no idea what your personal collection consists of. In the old days we all bragged about our collection sizes. 2,000 Albums was considered very large.

and

As I See It, now-a-days and into the foreseeable future , Qobuz is becoming everyone's music collection!

I'm getting the impression that reviewers are doing complete reviews using streaming services as their source.

Mr.HR suggests that he is down to only a small few vinyls ( under 400ish ), I've been 33.3 inactive for 35 years and have more than that.

As a personal note, I'm an Industry watcher, not quite an audiophile. I do buy a few pieces for resale and I do purchase gear reviewed by Stereophile. Mr.Atkinson has always been the "truth teller" for all Audiophile Press. For a while, Mr Tyll was a reliable reference. I admired Mr.JA from my days living in the UK ( 1980s ) somuchso that I imported and sold subscriptions to HFN&RR here in the States. ( Gary Market Style )

I'd felt that your analysis of MQA was reliable and responsible. I regretted the incredible barrage of negatives needing constant batting down. ( still need batting down ). I was importing Meridian in the 1980s.

Looks to me that Industry reporting remains intact with you at the helm. We all need a stable Print Press doing umbrella coverage for such a diminutive niche interest group of commitedly serious participants. Stereophile's editorial content to noise ratio is far beyond any Glossy I've ever encountered. Phew!!!

Mr.JVS needs a YouTube channel.

Thanks for writing back,

Tony in Venice

Jason Victor Serinus's picture

I appreciate this, Tony. Not sure I'm ready to take it on. Living in Port Townsend, WA is not exactly the same as living in NYC or Brooklyn. But perhaps some of the deer, raccoons, and coyotes are audiophiles. We shall see...

jason

SamB's picture

Really enjoy this review.
Equipment, comparison and music.
Thanks

Jack L's picture

Hi

Yup. Simplicity is unique beauty of Pass 8 = musically friendly !

Quite a 'diversion' from current trendy balanced-input amp design.
Personally I don not advocate balanced-input design as I consider it a marketing gimmick rather than a practical function.

Balanced signal transmission has been historically employed in application of very long runs audio signal cables, e.g. in recording studios A & outdoor PA systems to prevent hum/noise got into the audio signals passing through the cables.

Who needs balanced signal transmission at home anyway where the interconnects are relatively so so short ?

Less electronics better sound = my circuit design philosophy! Quite like Nelson Pass, right ?

F8 is probably the simplest audio power amp design I have ever read so far. I love its simplicity big bigtime.

That said, I notice Nelson purposely designed F8 single-ended Class A output power stage using one only N channel JFET instead of single-ended push-pull complementary (Output Capacitor-Less OCL) topology used by ALL other designers.

By using one output device will therefore NEED an output coupling capacitor to prevent DC from the power JFET from damaging the loading loudspeaker.

Though Nelson claimed the output coupling caps (2 large electrolytic caps shunted by a HF friendly PP cap) get no problem of LF down to one HZ !

But does it affect the fluidity of the complex harmonic music signals ???

I can see why Nelson purposely used single JFET output device instead of conventional fully-symmetrical complementary design. The latter topology will cancel the second harmonics in the music signal which he strongly advocates for the last many years.

IMO, correct me if I were wrong, the F8 output power stage he incorporated his proprietary out-of-phased 2nd harmonic distortion generating topology as published in his F8 papers.

He believes our ears like reversed phased 2nd harmonic distortion.

Great mind, Nelson !

Jack L

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