Blue: Lieven’s Impressions
The C421 I received is not the production model Mike has but it also has the OPA2227 op-amp. First time I saw the latest JDSLabs creation I was impressed. It’s a very nice & basic design with a brushed aluminium case, it is slim, simple and it is light. Measuring only 97,5mm x 14mm x 62,5mm this portable amp is about the same size of a pack of cigarets but more slim and it fits perfectly in my pocket. As with other portable amps the 3.5mm in- and output is located in the front where you also have the tiny but firm bass and gain switches and the volume control. They have all been very well incorporated in the design and I don’t see any risk of them breaking or switching on/of while it being in your pocket on the go.
Battery life is reasonable with 11h stated by the manufacturer. Compared to some other (bigger) portable amps like the JustAudio µha-120 (24h) this is on the low side. In it’s defence, you can use it while charging and it chargest fast: 80% in 2 hours, and 100% in under 5 hours time!
In contrast to Mike’s production model mine has some minor issues: The gain is very high and you can only use the volume control for a few milimeters. There also is a slight channel imbalance at very low listening levels, the left channel starts a little bit later as the right one and as a result I had to lower the volume on my source to have a better use of the volume control. Mike’s version of the C421 doesn’t have any of these issues so they have all been fixed during development, which of course is excellent news. Must be hard being a producer sometimes but JDSLabs succeeded on eliminating these issues making it one hell of a portable amp.
The amp is absolutely dead silent, it doesn’t make any noise it’s not supposed to and while turning the volume knob you don’t hear any cracking or “dust”. Since the very first minute I turned it on I’ve loved the sound of this little amp, it is just great to listen to. With my version of the C421 I never had to use the high gain setting and JDSLabs also advises to only use it when you really can’t get enough out of it at low gain. Normal gain (production version) is 7,2db and high gain is 16,9dB according to JDSLabs’s website. I had no problems at all driving any of my headphones, and of course while there still is a difference in performance of a portable amp and a full desktop amp, it drives all headphones to very loud volumes.
The bass/flat switch on the other hand I have used at multiple occasions. With the flat setting you get a very neutral soundsignature perfect for classical, jazz and a lot of other musical genres. For my taste it could have used a bit more bass impact but by switching on the bass (+8dB peak) it transforms in a little bass monster, perfect for popular music and dance music and I actually found myself keeping the bass “on” most of the time. In Mike’s version the “flat” setting has a bit more impact making it very enjoyable for the average listener not requiring a lot of bass impact.
Overal the C421 sounds very smooth and enjoyable with a perfect black background and o so very slightly dark sound. To be honest, I can’t really call it dark. It’s so non fatiguing that I can listen to it all day long, as a matter of fact that’s exactly what I am doing at the office. The sound the C421 produces is very clear, transparent and has a perfect balance. Detail retrieval is great even with the bass boost on, mids are smooth and warm and the treble is just perfect to my ears: not too harsh or bright but just right. Soundstage is excellent for a portable device, certainly at this price point but of course it can’t compete with a full size desktop amp.
I don’t know if the JDSLabs C421 has gotten its name from the small Cessna C421 airplane, but the JDSLabs C421 sure does fly just as high! I really like this amp and if JDSLabs keeps up this level of sound at this price point ($184)I am very curious what they will bring us in the future. This is a winner for sure!
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