For sale


updated: Mar-19-2023

post separation

support this website

On this page headphones (and sometimes audio equipment) that were bought, sometimes 2nd hand, for testing/review purposes.
With the (usually only partly) recovered funds I can buy and measure other stuff.

This is not a webshop so when interested in something you need to contact me (solderdude) or by filling in the contact form.

Treble peak filters & attenuators

Custom made passive filters, passive attenuators and/or headphone extension cables can be made to specifications on request and is a way to support this website. (global shipping possible)

Kameleon PCB’s

Built filter modules for Kameleon (on request) around € 20.-

prices of bare (not populated) PCB’s  & boards in stock (Sept 2022):

Kameleon in-line board (black) = 9.10 now € 8.30                in stock: 8
Kameleon 2.1 amplifier board (black) =  € 7.10     in stock: 7
Power supply board
for Desktop Kameleon = € 12.30            in stock: 10
Filter Module PCB (SMD, black) =  € 1.70               in stock: 32
Crossfeed Module PCB (SMD, green) = € 4.60       in stock: 2
Kameleon v 1.0 board =
now  € 3.00                     in stock: 3
Filter Module PCB (TH, green) = € 1.00                 in stock: 13 (not suited for inline Kameleon)

The headphones below are (preferably only) sold within the E.U.
Prices are without shipping costs.
Shipping outside of E.U. is possible but quite pricey and taxes/importduties may be added as I only ship insured.

HIFIMAN HE 400i (2020) used in as new without box: € 110.- (with external filter: € 125.-)HE400i-2020 kl

HIFIMAN HE35X modified (1 left !) € 59,- basically new in box but better sounding.
Very good sound quality when on a budget!

HE35X kl

Beyerdynamic DT240 Pro new in box, only used for review. €50


Denon AH-MM200 white as new in box €45AH-MM200 kl

Sennheiser HD400S as new in box €30


AKG K240 studio used, in box. € 35.-  (with velours pads: €50)

K240 studio kl

Superlux HD668B in stock form in box with acc. as good as new. € 20.-
With velvet pads and toilet paper mod € 30.-HD668B kl

Koss KPH30i (lightly used in box) € 15.- with (imitation) Grado bowl pads € 25.-

KPH30i kl

audio-technica ATH-A700X (fixed) used. €50 filter can be included for €15.- extra.


audio-technica ATH-AD700X used and modified (can be undone) in good condition, no box. € 50.-

Sennheiser HD570 Symphony, used, modified and refurbished: € 35.-

Sperlux HD330 (modified) new in box € 29.-

DAP HP-280 Pro (used) € 45.- modified headband (dark red) filtered and with velour pads.

Sennheiser HD520 used with original and/or aftermarket pads € 30.- / € 40.-HD520

Sennheiser HD430  heavily used € 20.-

HD430 kl

Pioneer SE-305
(vintage coconut) for € 15.-