The L300's respond only modestly (to a point) in to boosts in lower frequencies by conventional methods such as EQ'ing and source chain. To get proper bass response,
unconventional methods are needed (see below).
On the contrary. Double amping often results in very nominal loss in
perceived signal purity, and even a more preferable sound depending on the configuration. 'Impedance mismatches', while may be a thing are more common connecting two outputs in parallel to another input (an amp with dual inputs) than an output to another input. You got the notion of 'introducing distortions' quite wrong as well. First off, distortions are often more of a blessing than a curse in this hobby. Innumerable headphones with fairly high measured distortions as well as DACs are actually preferable to many of us in this hobby.
There are good and bad distortions and it is a subjective matter. It's one of those grey areas where science alone cannot explain why a sound can be more preferable to some even though it may not measure well on paper. And that's the whole concept of tube amps in general. The tubes introduce varying types of harmonic distortion, as do all old analog-era (eg 70's) stereo & recording equipment which are often regarded as superior in organic / natural sound than today's digital systems. But moreover I believe the above user was referring to using the tube amp as a
tube-buffer / preamp (connected to his energiser via the line-out).
THIS folks is THE WAY to go, and IMO the ONLY way to go with many electrostatic headphones such as the Lambda's. My years of owning several tube amps as well as multiple e-stat setups and dozens of comparisons even public exhibitions of said setups has always shown an unwavering favor towards the tube-buffer method with e-stats. Transforms what can often be a cold / dry / sterile sound into something more full of life with vibrant mids, weightier lows, sweeter treble, larger soundstage and more organic / lifelike overall. One can also consider that some of the best e-stat and conventional headphone amps alike are tube amps as well (WA-33, Blue Hawaii, Orpheus 1 & 2, etc.), because of the good type of controlled distortion.
The likely reason of the somewhat tame bass response on the Stax L300's
Lower frequencies move more air and are thus need to 'breathe' in order to be in full effect. Most headphones achieve this by way of perforation or breathable mesh sheets in the diaphragm around the driver inside the headphone, allowing this air to dissipate out of vent holes in the outer earcups. Headphones either without a perforation in the diaphragm or that don't have a diaphragm around the driver such as the L300's benefit when they don't 'seal' around your ear. This was something that me and a custom headphone modding hobbyist / designer had realized. Indeed you can see the effect of this increased breathing area when you pull the L300's 1-2cm away from your ear, often producing a more voluminous bass but uncontrolled.
My recommended solution
Below is a summarized copy of my post on
this thread which discusses many excellent options for altering the sound of the L300 L.E.'s by way of earpad rolling, which to myself and others who have tried it, have noticed substantial and widely varying results dependent on chosen earpads. The one below actually not even requiring a different earpad, but an adapter and specially placed vents between it and the L300 L.E. earpad (said to be the same as L500 pads).
Stax L300 LE pads (said to be the same as L500 pads) on SoCas PadMod 6mm spacer
Using blu-tac to fill 50% of the space between the spacer and adapter; three approx. 1" size pieces on each side resulting in good air ports as shown
- Upper left: SoCas PadMod 6mm spacer attached to my original Stax L500 earpads (filled 50% with blu-tac between these for best bass definition)
- Upper middle: SoCas Padmod for Stax L300/500/700 XB Mount non-ported
- Upper right: Stax L300 limited edition, with Brainwavz oval black PU/Velour earpads compatible with ATH M50, (on) SoCas Padmod for Stax L300/500/700 83x108mm non-ported
- Lower left: SoCas PadMod 12mm spacer
- Lower center: SoCas Padmod for Stax L300/500/700 XB Mount ported
- Lower right: SoCas Padmod for Stax L300/500/700 83x108mm ported
By far the best soundstage, bass quality, technical proficiency in all areas. An absolutely uncanny ability to faithfully reproduce instrument separation / imaging, width, texture, detail and a bass that while maybe not the most powerful has real definition in droves.
The only difference between this and stock L300 limiteds is the spacer adapter and specifically placed port holes between the spacer and earpads, but somehow this really brings the bass into focus while retaining the best texture available, and even increases the soundstage by a little while not being overdone, and simultaneously seems to do a fairly good job fixing the somewhat off-kilter or hollow tonality of the original configuration. I also tried a 100% blu-tac seal which caused a void in bass, and 75% seal which was still bass light, but you just can't go wrong with the above 50% configuration!
I also tried the stock earpads with the 12mm spacers and got a phenomenal soundstage, but the fit was not practical.
Final comments / notes
Usage of all earpad adapters and spacers strains the headband horizontally which can shorten the height of the headband thereby increasing pressure points on both the top of the head and the upper section of the earpads, as well as increasing clamping force. For those with a large head size I would forgo this route unless you are able to find a way to replace the Stax headband with a larger one.
- I highly recommend the Brainwavz oval black PU/Velour earpads compatible with ATH M50 on SoCas Padmod for Stax L300/500/700 83x108mm non-ported adapter for a very robust, weighty, balanced sound that's fantastic for rhythmic centric genres such as electronic music including EDM, pop and hip-hop.
- And above all I recommend the (above) Stax L300 LE pads (said to be the same as L500 pads) on SoCas PadMod 6mm spacer with a 50% fill of blu-tac between spacer and earpad, especially for analogue era atmospheric / orchestral / classic rock material for a truly master-class experience.
Both of these pairings are so exceptionally great that I never want to take them off! In fact these both sound not only so fantastic but also distinctive that I just may order a 2nd pair of L300's so I can have one headphone for each sound signature... they're THAT good!