Pioneer A400 upgrade & Red Hill Audio

[KidKomet]

Afternoon all!

Has anyone had any experience with an Upgraded A400? I know Tom Evans used to do them but the only upgrades I can find now are from Red Hill Audio. Naturally, I can't demo this upgrade before I buy so I was hoping someone on here would have some hands-on with them.

Many thanks.

 

[MUSICRAFT]

Hi KidKomet

What speakers and source component/s do you use please?

All the best

Rick @ Musicraft

 

[KidKomet]

I have some KEF Reference 103/4's and naturally a standard A400 is not really capable but it's in mint condition and didn't cost me anything so I was wondering if upgrading it would be a better route than blowing £1000+ on a suitable amp. My source will soon be a Yamaha CDN500 and my PC.

Thanks

 

[MUSICRAFT]

Hi Kidkomet

If the amp is operating to its full specification and as long as you're not after disco like levels then I'll recommend you should instead look at higher quality source and speakers.

All the best

Rick @ Musicraft

 

[BigH]

Depends how it will cost to upgrade? I believe the A400 is nearly 20 years old, I would be inclined to look for more recent used amps for around about £600, brands like Creek, Exposure, Sugden and Leema spring to mind.

 

[Vladimir]

The biggest upgrade you can give a Pioneer A400 is a proper cleaning of all contacts, switches, volume pot, trim pots.

Second best is adding bigger smoothing caps (I added new Elna for audio 2x12,000uF) and upping the quescent current to 180mA.

Third best upgrade is changing the volume pot to ALPS Blue Velvet and bypassing the balance control and input selector (you basically get a power amp with a volume knob).

I also changed the stock power cord with a new one (3,5kW limit).

Lots more mods you can do to the A400, just google arround. WHF and diyaudio.com have some threads about this.

 

[KidKomet]

Excellent, Thank you!

 

[hybridauth_Facebook_1178400182]

Just upgrading my 25 year old A400 too. Plan on replacing smoothing caps with Panasonic equivalents and also replacing the coupling caps with Elna Silmic II. Already edged the bias current up to 150ma.

I was thinking of changing some of the other caps but have a pretty basic question - how on earth do you easily identify the components from the solder side/bottom of the PCB? Easy enough from the top with the schematic and components are numbered anyway.

Thanks

 

[TrevC]

The biggest upgrade you can give a Pioneer A400 is a proper cleaning of all contacts, switches, volume pot, trim pots.

Second best is adding bigger smoothing caps (I added new Elna for audio 2x12,000uF) and upping the quescent current to 180mA.

Third best upgrade is changing the volume pot to ALPS Blue Velvet and bypassing the balance control and input selector (you basically get a power amp with a volume knob).

I also changed the stock power cord with a new one (3,5kW limit).

Lots more mods you can do to the A400, just google arround. WHF and diyaudio.com have some threads about this.

I get the smoothing cap idea but what's the point of the rest?

 

[Vladimir]

The biggest upgrade you can give a Pioneer A400 is a proper cleaning of all contacts, switches, volume pot, trim pots.

Second best is adding bigger smoothing caps (I added new Elna for audio 2x12,000uF) and upping the quescent current to 180mA.

Third best upgrade is changing the volume pot to ALPS Blue Velvet and bypassing the balance control and input selector (you basically get a power amp with a volume knob).

I also changed the stock power cord with a new one (3,5kW limit).

Lots more mods you can do to the A400, just google arround. WHF and diyaudio.com have some threads about this.

I get the smoothing cap idea but what's the point of the rest?

The pot is cheap rubbish and after years of use it needs replacing. Worn tracks can't be fixed with spraying servisol/deoxit. Might as well add a nice smooth feeling conductive plastic ALPS pot. Considering you can't get a pot like the original one (both for volume and balance), you lose the balance facility by replacing it.

I changed the stock cord since my A400 had the original one cut off to accomodate schuko plug. After few hours of operation I could notice the power cord got warm to the touch. When I removed the electrician's tape to solder the wires properly (were just twisted together), I noticed they were corroded and green pitted throughout the cord, so I changed the whole thing completely. I had a thick extention cord laying around and it did the job nicely.

It really is refurbishing and restoration process of a 24 year old amp. Not much of an upgrade.

 

[dim_span]

I have a few of the Tom Evans upgraded components (I have the Pioneer Precision amp, the Precision CDP and a Precision tuner)

Acording to Tom, the Pioneer Precision (upgraded Pioneer A300R) is sonically better that the upgraded A400 (he called this one a GTE) ....

He no longer upgrades the A400, but still does offer upgrades on the Precision A300R .... If you go for the 'full monty' upgrade, you loose the Phono capabilities (you cannot connect a deck to the amp)

 

[Jamo]

Hi All,

Let me first caveat this by saying I'm not very technical at all...

I purchased a so-called "mint" Pioneer A-400 last year but the RCA sockets are all coroding / coroded and need to be replaced. I took the amp to a chap for repair who says he can't get hold of the replacement RCA modules.

Does anywhere know where I can get these modules from or take the A-400 to get the repair / replacement of the modules done for me? I live in SW London.

Thanks all.

James

 

[TrevC]

Hi All,

Let me first caveat this by saying I'm not very technical at all...

I purchased a so-called "mint" Pioneer A-400 last year but the RCA sockets are all coroding / coroded and need to be replaced. I took the amp to a chap for repair who says he can't get hold of the replacement RCA modules.

Does anywhere know where I can get these modules from or take the A-400 to get the repair / replacement of the modules done for me? I live in SW London.

Thanks all.

James

I think it unlikely they are available. Try squirting them liberally with Servisol, squirt right into the socket, and pluggiing and unplugging repeatedly.

http://www.ebay.co.uk/itm/Servisol-Super-10-Switch-Contact-Cleaner-/281517609818?pt=LH_DefaultDomain_3&hash=item418bc1d35a