Jun 6th, 2023
Vince used to work for Apt and has developed certain upgrades to increase the reliability, longevity, and also the fidelity of these already remarkable preamps and amplifiers. The APT 1 Amplifier and Apt Preamp upgrade consists of three levels to suit your modification needs.
If you are looking for the APT 1 Upgrades and Repairs (Read about them here)
APT Holman Preamp Upgrade: YES ! we are definitely providing these upgrades at the current date.
Level 1: We repair the obvious faults and clean all controls and switches. We replace any obviously bad capacitors and do only minor upgrades. This level costs $148 plus the cost to ship it back to you (approximately; $34 eastern states, $36 mid-west, $45 west coast U.S. ) . Be sure to include this payment, Check or Money order, Sorry NO VISA or PAYPAL
Level 2: For the Level 2 upgrade, we complete the Level 1 upgrade and replace certain components that are critical to the fidelity of the machine. The critical components are upgraded to the correct type of part for the circuit design (e.g., non-polarized capacitors in certain op amp circuits and Mylar caps for other circuits which require higher specs in the equalizer or power supply). Not all capacitors are replaced. The cost for this level is $330 plus return shipping (approximately; $34 eastern states, $36 mid-west, $45 west coast U.S.). Be sure to include this payment, Check or Money Order, Sorry NO VISA or PAYPAL.
Level 3: This is THE audiophile upgrade! We do the Level 2 upgrade, then replace all capacitors and other crucial fidelity components. This costs $440 (worst case scenario; some units will cost less) plus return shipping (approximately; $34 eastern states, $36 mid-west, $45 west coast U.S.). Be sure to include this payment, Check or Money order, Sorry NO VISA or PAYPAL This price does not include replacement of the transformer, volume control (which is seldom ever bad), or the main mode switch. If these are needed, the upgrade may cost more. The price includes the matching of channel parts (FET's, op amps, etc.) for noise and performance, as well as some esoteric modifications. The modifications are done to satisfy those golden ear types who may possibly hear the subtle difference of some very critical capacitors in the audio path (e.g., there are a few stages that can benefit from capacitor bypassing with high quality Mylar capacitors, improvement of subsonic filter for advanced wider frequency response, less phase shift, etc.). Admittedly, I don't think the sonic improvements are immediately obvious and dramatic (unless the unit had major off-spec or failed parts), but it is true that listeners who do own high quality, reasonably phase correct speakers playing quality, acoustic-oriented program material will hear an improvement. Let me stress my opinion (which is based on factual A/B blind testing and reinforced by AES Journal testing competitions) that the subtle differences of improved spatial/depth or instrument timbre clarity are mostly perceived due to the quality of the speakers and their appropriate listening position. (Read more about how speakers relate to audio upgrades here) . But moreover, the level 3 mod will probably extend the life of the product by many years.
Update June 2023: Minor price increase to $330 (level 2), $440 (Level 3) due to a few adjustments in service with slightly improved components, as well as parts pricing and availability issues resulting from supply chain delays and tariffs. We continually strive to find the best solutions for the highest quality service, performance, and reliability. We wouldn't do it if it wasn't worth it.
Other Mods Included in Level 3 are: conversion of mode control to more effective stereo imaging enhancement (very audible). Phono input has precision infrasonic low filter built into input stage, dramatically reducing warp noise modulating the audio. A minor correction to tone control equalization for more likeable equalization and precision. For CD, vinyl, etc. highest quality mute relay install (same part used in pro industry recording consoles like Amex, Neve, etc.). Frequency response, transient response extension (virtual no phase shift from accumulated coupling capacitors). High quality Panasonic non polar op amp coupling capacitor where required board wash of alcohol and special dielectric lube into tape and line input switches for longest life (a simple exercise of switches will revitalize lube to clean oxides on contacts again and again!) The change to specifically corrected values and types of capacitors has proven to cause a slightly better reproduction of impulse and transient response in the musical spectrum. A listener might hear the bass impact has been improved, making the music a little more dynamic sounding
Please be aware there is a NON REFUNDABLE $88 diagnostic deposit fee on all APT Preamp Upgrades. (This amount will be subtracted from the total cost of the upgrade)
If you want to have this service / modification for your Apt Holman preamp ,complete our service request form here: https://www.audioproz.com/AP.php?Inquiry=Services
PLEASE CALL US DIRECTLY BEFORE SHIPPING ANY UNIT at 617-926-8020 (weekdays 12 noon to 7 PM, except Tuesdays).
PLEASE, when shipping you must wrap the face in 3 layers of bubble wrap and double box with second box which has a little space to fill with paper etc. The APT preamp is very heavy and can punch thru a box which travels across the country. Luckily very few have suffered but double box - don't let UPS box it for you.