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Denon DVD-3910 Underwood Mod

by Arvind Kohli February 28, 2005
Denon DVD-3910 DVD player

Denon DVD-3910 DVD player

  • Product Name: DVD3910 Audio Supplemental
  • Manufacturer: Denon Electronics USA
  • Performance Rating: StarStarStar
  • Value Rating: StarStar
  • Review Date: February 28, 2005 19:00
  • MSRP: $ 2930


  • Upgrade the I-V, ANALOG FILTER and OUTPUT BUFFER op amps with dual op amps from Analog Devices, mounted to special surface mount to surface mount vertical adapters. The 3910 Level 1 Mod uses (4) pcs. of these dual op amp upgrade modules.
  • The output stage is biased into CLASS A.
  • The output RCA jacks (1 pr.) to VAMPIRE RCA jacks, using a base material of OFC-Copper (3.5 times more conductive than brass), and direct gold-plated...no intermediate nickel-plating at all!
  • Stock unit output signal currently exits via a miniscule tin/lead plated PCB trace. The mod uses (4) pcs of pure 99.999% 23-awg solid-core silver DH LABS wire...with foamed teflon tape-wrap insulated.
  • The signal resistors (22 in all) are changed to Japanese made RIKEN OHM Carbon Comp type, with gold-plated copper leads (replacing cheap, magnetic, China-sourced, metal-film resistors).
  • All critical caps are changed to Electrolytic types (2) for the new (2) AuriCap metallized polypropylene coupling caps + "paralleled" BLACK GATE FK-Series coupling caps (2), replacing the generic electrolytic caps in the stock unit.
  • Precision 1% POLYSTYRENE film and tin foil caps (14) were used in the analog filter, replacing tantalum caps in the stock unit.
  • The chassis resonances have been dampened with SOUNDCOAT (2 sheets - 1sq. ft.) and external vibrations have been isolated via (4) large compliant EAR sorbothane feet.
  • The Power Supply and digital stages are been upgraded with (15) BLACK GATE FK, NX, STD series electrolytic caps (replacing cheap ceramic and/or generic electrolytics)...and all critical analog supply diodes (currently generic quality) have been replaced with ultra-fast soft-recovery FRED type diodes (4) Vishay-Telefunken and (5) International Rectifier HEXFREDs.
  • WBT 4% silver solder throughout.
  • The mod takes approximately 7-hours to complete.
  • The price of the 2-channel Level-1 mod is $1050 to customer units
  • New Level-1 modified machines are available for $2190
  • Level-2 mod improves the unit even further by adding:
  • Burr Brown OPA-627 Opamps in custom surface mounting boards.
  • Two Rel-Cap TEFLON TFT-Exotica bypass caps are added.
  • The price of the 2-channel Level-2 mod is $1250 to customer units
  • New Level-2 modified machines are available for $2450 Other available upgrades

Other Available Mods

  • To add an upgraded MASTER Reference Clock from either LC Audio or AudioCom will add another $480 USD installed (Clock, Custom Power Supply and Install Labor).
  • To perform an equivalent L-2 quality center (3rd) channel mod, adds $600.00
  • To do all 4 "additional" L-2 channels (3-6) would "bundle" together for $1900.
  • To add a pair of BYBEE "Slipstream" Quantum Purifiers to the power supply (just after the AC line input) would add $180/pr., installed.


  • State-of-the-art video connections including DVI and HDMI.
  • State-of-the-art video processing, including upscaling to 480p, 720p and 1080i.
  • Outstanding 2-channel audio playback quality.
  • Plays both hi-rez audio formats, SACD and DVD-Audio.
  • Compatible with virtually all current disc formats and file types.


  • Considerable investment in light of upcoming Bluray and HD-DVD technologies.
  • Remote not programmable and only partially backlit.
  • Voids manufacturers warranty, however Underwood offers a 90 day warranty on the entire machine and one year on all their work


Continuing on my series of disc-player reviews, I wanted to incorporate at least one “modded” unit. I am of the opinion that to extract the final ounces of fidelity a component has to be thoroughly tweaked; beef up a power supply here, change a connector there, upgrade a capacitor elsewhere, etc. Each change in itself may not yield an audible improvement or change, but layer on several changes and you can yield a substantial improvement. This pursuit is certainly as much art as it is science, and is also replete with snake-oil and dubious claims. In the end the only thing that matters is what a component sounds like, and that is what I intend to find out here.

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