Gramophone Desires # 43: First Watt F8 energy amplifier
I spent my childhood summers on Reichert Farm near Turtle Lake, Wisconsin, where my uncle Harold played 78 rpm records for his cows in the 1880s red barn.
He used a reared Victrola, which sat on a shelf directly in front of the cows, directly beneath a framed reproduction of an alpine landscape painting. He said the music and the mountain scene relaxed the cows and made them give better milk. Harold played the same Gustav Mahler symphony every day. I remember how quickly each CD ended, how I had to run over and switch them, and how angry he got when I played the CDs in the wrong order. I remember how the room smelled of hay and wet cow cakes, how half the sound of the Victrola was a scratchy, hissing noise, and how Mahler’s (and Harold’s) Austro-Bohemian German dominated the room.
Those sensual memories of the farm came to mind while watching a movie, Desperate Man Blues, about an infamous 78-rpm radio disc jockey and record collector named Joe Bussard, who explains that he has many of his most precious discs found by knocking on the doors of houses without electricity. In one case, you walked waist-deep through a swamp to get there. Joe Bussard is a legend. Watching him play rare records from the 1920s in his wood-paneled cellar is the purest example of what an advanced, 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 that contains thousands of brown-sleeved, unlabeled, deliberately disorganized 78-rpm discs. In front of him are several turntables, including his current favorite, a Technics SP15 with an Audio Technica ATP-12T tonearm. By his side is a 1970s-style equalizer amplifier with faders that he plays like a dobro (which he also plays) and a shelf with a number of tape decks.
In a corner at the end of the record wall, at least 25 minutes away from his DJ command post, sits a single Altec Laguna loudspeaker positioned in the corner, which is definitely not an Altec. But what is it
I posted this picture of Joe’s blonde wood corner speaker on Facebook and asked my friends if they could identify it. 25 people guessed wrong. Then I came across an article on Joe Bussard by Sound & Vision editor Al Griffin, in which he described the speaker as a “furniture type”. Fascinated, I wrote to Al and asked if he knew the make or model. “As you say, Joe Bussard is a sophisticated listener, but not what we would call audiophiles,” replied Al. “He didn’t bother with any front-end equipment other than cartridges and needles, and couldn’t tell me the brand name or model of his speaker. I called it a ‘furniture’ speaker because it’s probably a DIY creation, which he took up a yard sale. ”
Joe starts his listening by pulling a CD out of the stacks while telling a little story about the artist or where he found the CD. Next, he chooses a cartridge and pen, then adjusts the turntable speed, usually ± 1 to 3 RPM. As the recording plays, Joe quickly adjusts the EQ (which he does for each disc). This EQ adjustment is an important moment as it shows that Joe knows what these recordings are supposed to sound like, and he knows how to get that sound. With the 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 dedicated his entire life to listening.
First watt F8
The first solid state amplifier I ever used was a Dynaco Stereo 120 which I thought sounded nasty. The second was a homemade 20 wpc class A stereo amplifier. It sounded much better but went up in flames in the second week of life. The third was a Hafler DH-200, which I built as a kit and then fooled. After that, I auditioned and dreamed of owning the Electro Research A75 designed by John Iverson, the AMP-1 designed by Andy Rappaport, the Mark Levinson ML-2 designed by John Curl and the Krell KSA-50 designed (but I could not afford) by Dan D’Agostino and last but not least the first product from Pass Labs, the Aleph 0 designed by Nelson Pass.
Now if I could have one of those dream amps it would be the Electro Research A75. And the Pass Labs Aleph 0. Both. I recently heard an Aleph 3, the successor to the Aleph 0. It got John DeVore’s orangutan O / 96 speakers to sing with sweet, beguiling ease.
Nelson Pass has been designing amplifiers without interruption since Threshold Audio was founded in 1974. Since then, the sound of a pass-through amp has evolved not only more convincing and definitive, but also more subtle and sophisticated – especially its recent, more esoteric designs for First Watts (footnote 1).
Since writing for stereophiles, the Pass Labs XA25 and INT-25, and the First Watt SIT-3 and J2 have become must-have verification tools that satisfy both the romantic and technical sides of my brain and remind me of my solid-state on a daily basis – Dream amplifiers work in Class A. When the First Watt F8 was announced (for release in September 2020) I emailed Nelson asked what another low power JFET Class A amplifier could possibly add to the which I had already received from the J2, which I discussed in September 2016. He also replied by email: “I wanted to develop yet another amplifier with the SemiSouth SiC R100 power JFETs. So in 2015 I developed a design with the same output stage , but an alternate front-end circuit. Over the years of, I’ve put some more work into it, and now we’re finally releasing it a ls F8. “(For the next two paragraphs, the words are his, but the focus is on me.)
“The F8 is a two-stage stereo single-ended Class A amplifier with the [new-old-stock] Toshiba 2SJ74 P-channel JFETs and SemiSouth R100 SiC power JFETs for signal amplification and IRFP240 MOSFET mu-follower power 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 that operates as a current feedback amplifier (CFA) as opposed to the voltage feedback differential input (VFA) of the J2. This front end is more consistent with The single-ended approach to the amplifier design provides a cleaner second harmonic character, less distortion with 5 dB less negative feedback, wider bandwidth, and higher attenuation factor simple circuit is shown schematically. As I can best see from the distortion performance diagrams in the manual, at 1% THD the F8 outputs 25 Wpc into 8 ohms and maybe 13 Wpc into 4 ohms. The input impedance is 100 kOhm. The output impedance is 0.2 ohms.
I asked Nelson how readers could tell if the F8 would be effectively driving their speakers.
“Since the F8 is an extension of the J2, their similarities help here,” he replied. “The J2 has always been very good with efficient speakers (90 dB and more), which of course have good dynamics and an impedance above 8 ohms. Both are satisfied with lower impedances, but deliver less power below 8 ohms.
My experience shows that choosing a speaker with high impedance and benign phase characteristics is more important than high sensitivity.
Typically, power amplifiers develop a voltage gain of 25 to 30 dB. The first watt J2 makes 20dB. The F8 only delivers 15 dB, which is unusually low for a production amplifier. So I don’t recommend driving the F8 directly with a volume-controlled DAC. For this test I used a Rogue RP-7 preamplifier, which in symmetrical mode produces a maximum of 14 dB gain single-ended and 20 dB gain. Unlike the J2, which has both balanced (XLR) and single-ended (RCA) inputs, the F8, which is a standalone single-ended design, only has single-ended inputs. The list price of the F8 is $ 4000.
Listen with DeVores
My upfront plan was to use the easy-to-drive DeVore Fidelity Orangutan O / 93s (10 ohm nominal impedance) 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 to work well with the DeVores. For a bit of tube-versus-transistor fun, I thought I’d finish this column off by adding the 25-wpc single-ended solid-state F8 to the 22-wpc single-ended 845 tubed line -Magnetic LM-518 IA compare.
F8 against J2
I started my comparisons with the J2 to play Carlos Cipa’s Correlations (on 11 pianos) (24 / 44.1 FLAC Warner / Qobuz). With the J2’s rendering of the picturesque tone and hypertextured space of the recording, I immediately felt guilty about how long it had been since he drove the orangutans.
Footnote 1: Pass Laboratories Inc., 13395 New Airport Rd., Suite G, Auburn, CA 95602. Tel: (530) 878-5350. Web: passlabs.com