Is an Apt preamp a good preamp for my setup.

My system is a marantz cd-67se connected direct to a BEL 1001 amp with the sound fed into a pair of wharfedale diamond II's. Have a chance to purchase a Apt preamp and wondered if it would be a good fit to my system. Plus does anyone currently run the Apt, how do you like it and do you have a copy of the owners manual. The one forsale does not have the manual but it does have the schematic sheet attached to the bottom.
So old its bound to be widely out of spec, if you do buy it , hook only to some speahers you can live without. Been there, done that.
The Holman pre was a ahead of it's time, regarding presentation(for a SS design). If you can get it for less than $200; this is a good place to get it updated: (
I owned one and found it lifeless. Yes, ahead of its time in the 1980s, but much has changed since then. And perhaps, mine was out of spec. I would look elsewhere such as Audio Refinement or any other very decent preamps.
Did some more research on it and found the most common problem with the apt preamps are mute relay going bad and sometimes the power button going out. Do not know if the previous owner replaced or upgraded anything on this unit. Anyway to tell if its a generation 1 or gen 2 preamp? Have noticed that they are selling on ebay for 250 to 500 and there seems to be a demand for the 30 year old unit. Thanks for the link to APT/HOLMAN Repair Service, I also found Audioproz and the owner Vince Naeve worked for Apt as a tech. They do upgrades and service as well as selling nos parts for the apt preamps and amps. I was able to get a great price on the unit and the store said that they'd give me full refund if the unit had any issues. I hooked it up and have had it running since Friday at 6:30pm with two power breaks on Saturday at 3pm to 4pm and 6pm to 11pm. So far I've tested the unit with my cd connected to aux 1. Unit runs fine and the sound is pleasing and even across both channels. The switches and buttons all seem to work. If I open the unit up would there be tell tail signs as to if the previous owner replaced or upgraded anything. The store selling it had no idea on the subject.
Personally- I'd send the unit to either Angelfire or Audioproz and have it checked out. They could tell you it's generation(via the serial number)and if it has been updated. There are 70-some caps in the piece that can make or break it's sound. The only way you'd be able to tell if it had been restored, would be if the tech did sloppy work(unless Blackgates/Sanyo OS-CONs/Solens/Burr-Browns/HEX-FREDs/etc, had been installed and you knew for what to look). Happy listening!