Turntable Lab PH01 Phono Preamp + Headphone Amp
A deeper look into the development and features of our custom phono pre-amp, made in the USA.
In early 2016, we started the process of creating our own Phono Preamp. Firstly, we wanted an efficient phono preamp that sounded great and fit our visual aesthetic (Reid Miles meets Swiss monk). Secondly, we wanted to integrate useful functionality to make our preamp more than just a converter box. With the audio expertise of Collinsville, Illinois-based JDS Labs, we came up with the PH01.
P+H - Phono Preamp + Headphone Amp
The PH01 features both a phono preamp and a headphone amplifier. Both sound excellent (more on that below). There's a switch to select either output, and the single volume knob that works for both.
Volume Control for Minimalist Setups
We observed that turntable users are increasingly using a turntable plugged directly into powered speakers (what we call a "Minimalist Setup"). This setup bypasses the traditional amplifier, and relies on the speakers to control volume. This setup is space-saving and convenient, but if your speakers are spaced away from your turntable, the volume control is not longer located near your turntable. The PH01 brings that control back to your turntable.
Minimalist turntable setups also often lack a way to plug in headphones. The PH01 solves this fundamental problem without adding another component. We also added a Headphone Muting Relay to get rid of the pops that occur during startup and shutdown.
"This exactly what I needed to run headphones through my system. Thank you Turntable Lab for recognizing this problem out there for those of us going directly into powered speakers!" - Tamato
A pre-amp is just the pre-amp in the end. Your turntable should be the focus of attention. We designed to PH01 to be low profile and compact. It works well next to a turntable or on a shelf (like the Line Phono accessories shelf). The oversized DJ-style volume knob is easy to control from all angles.
Made In The USA?
Lastly, here's an interview with JDS Labs' Jude Hopper to go over the finer points of the PH01 and phono preamps in general.
In your opinion, what makes a good phono pre-amp?
Ultimately, we all want to enjoy music. A good phono preamp must nail the RIAA curve, while doing no harm to the experience.
Can you explain RIAA curve in layman's terms?
So we’ll start with the basics. All vinyl records have grooves. The grooves for lower frequencies (bass) are wider than the grooves for higher frequencies (treble), so recordings are made with high frequencies boosted to save space on the record itself. Applying the RIAA curve reverses this emphasis, which results in the original sound of the music, longer recording capabilities (whole albums), and a cleaner sound.
Can you tell us a little about how you picked the inner-components for the PH01?
Phono preamps consist of classic, analog circuitry. We built and listened to three RIAA circuits with unique component values. Once tightest EQ response was achieved, we selected Nichicon Muse series coupling capacitors and WIMA film capacitors for equalization circuitry, which our customers have consistently enjoyed in past filter projects, like cMoyBB. New Japan Radio opamps (NJM4556) are employed for both preamplification and headphone amplification, running on analog +/-12VDC supply rails.
How did you ensure quality control on the PH01 manufacturing?
At JDS Labs we do all of our machining in house with our 2 CNC machines, so this Turntable Labs Project was no different. We worked with the TTL team to figure out exactly what they were looking for in capabilities and aesthetics, all designed in-house by our mechanical and electrical engineers. We find that when you give yourself the capabilities to handle almost all of the production process, you can get the quality that people notice.
Every preamp is inspected at three points. Our production staff visually inspects the PCB, DC supply rails, and SMT amplification ICs, then proceeds to installation of larger, through-hole components. A functional test is performed after completing electronic component soldering, followed by a final listening test after assembly in the enclosure. Approved preamps receive a stamped inspection card.