advertisement


Audio Innovations Alto

Hi! I have to admit I am enthusiastic about this little amp too. I generally have an inclination towards Audio Innovations gear because of their sound, and I have owned a Series 500 valve amp, an ALTO mk2, and now I have an ALTO mk1. The latter is absolutely brilliant, and I'm not planning to replace it for a while (it also seems to be working well with my JPW AP2 speakers).

The piece I have emits a bit of transformer hum too, but I can live with that. What's really rather disturbing, is that sometimes one of the channels just disappears (it happens both to the left and right channel randomly). The local official Audio Note service has ckecked it, everything seems to be just fine with the main parts. My only guess is that the volume potmeter is giving up, mainly because if I play around with it for a while, the channel comes back (the potmeter is also very noisy sometimes, but not always). We have also excluded the possibility that the fault is before or after the amp.

Unfortunately, I was told in the service that they are no longer able to source the same kind of potmeter that is in the ALTO, or one that's fully compatible, and replacing the original part with a different one would require such a long and painstaking "bricolage" that I'd better believe I don't want to pay for that, considering their hourly rates. Could anyone give me some idea which part I should buy online, and try to fit it myself (it can also be an "upgrade" :) )? I would also consider a stepped attenuator, but I'm afraid there is not enough room in the ALTO's slim body to fit one.

Many thanks in advance for your suggestions.
 
It's worth looking at the main board to see if any tracks have deteriorated, or any dry joints. This happened to a chrome Chinese version one that my sister owns.
 
mandryka said:
Just spent some time comparing the (repaired!) AIto and the Radford STA 25, on my JR 149s. Lockdown boredom relief.
With all due respect to the Alto, it is just not in the same league as the Radford:
Click to expand...

I my experience, comparing any amplifier with the STA25 is a somewhat one sided game. I've not done extensive comparisons, but I've not found any power amplifier at any price that can better the STA25 within its power envelope. I've had two power amps that cost £1,000 and £3,000 more than a 'new' Radford revival STA25 and were really not in the same league if you want to listen to music. The fact that I got mine used at a really good price, makes it sound even better! I will never buy another power amp for my main system.
 
Balint Kekedi said:
...What's really rather disturbing, is that sometimes one of the channels just disappears (it happens both to the left and right channel randomly)...
Click to expand...

if I were you I'd first DeoxiT it, the most common problem with those ol' Noble pots is dirt inside the pot, either/both on the wiper or/and the resisitive track
 
coltrane said:
if I were you I'd first DeoxiT it, the most common problem with those ol' Noble pots is dirt inside the pot, either/both on the wiper or/and the resisitive track
Click to expand...
Hi, thanks, I have already tried to apply that fix, bit it didn't really help this time :( It must be either the volume potmeter, or something else which is harder to find (like deteriorated tracks, I guess). What is funny, is that the phenomenon occurs on both sides, never at the same time, but sometimes frequently switching sides without me touching the amp...
 
Balint Kekedi said:
Hi, thanks, I have already tried to apply that fix, bit it didn't really help this time :( It must be either the volume potmeter, or something else which is harder to find (like deteriorated tracks, I guess). What is funny, is that the phenomenon occurs on both sides, never at the same time, but sometimes frequently switching sides without me touching the amp...
Click to expand...

it then means that, first, you disassembled the amp, so you can read the value of the pot (printed on the metal case like 100K); second, knowing the value you can sure buy one new pot from the net - it's an ol' Noble, and I'm 100% certain it's still available (I did buy some for my S300 amps, only the value's different) > try e.g. eBay.com; third, the symptoms you say above do pretty much coincide with those of a worn pot. good luck :)
 
This site contains affiliate links for which pink fish media may be compensated.
I wouldn't mind picking up one of these. There is a lot to be said for a simple, single rail cap coupled amp. I regularly use a little vintage Pioneer SA500 built along these lines and with the right 'speaker choice it's a lovely amp. Nice with bookshelf 2 way vintage ARs :)
 
coltrane said:
it then means that, first, you disassembled the amp, so you can read the value of the pot (printed on the metal case like 100K); second, knowing the value you can sure buy one new pot from the net - it's an ol' Noble, and I'm 100% certain it's still available (I did buy some for my S300 amps, only the value's different) > try e.g. eBay.com; third, the symptoms you say above do pretty much coincide with those of a worn pot. good luck :)
Click to expand...
Hi, many thanks! :) Yes, I disassembled it a couple of weeks ago, and could read the value (100K). So far I couldn't find an identical one, but I'll keep looking. Does anyone have by any chance have the schematic of this amp?
 
This site contains affiliate links for which pink fish media may be compensated.
Balint Kekedi said:
Hi, many thanks! :) Yes, I disassembled it a couple of weeks ago, and could read the value (100K). So far I couldn't find an identical one, but I'll keep looking. Does anyone have by any chance have the schematic of this amp?
Click to expand...

Hi,
Forget about schematic...it's a SF...
Go for balance pot, check the track pads, 100% broken...
Couple days ago had problems with high DC offset on the left channel (-532mV) and after one week, found broken track pad between input transistors...barely visible!
Now, 12.2mV LC, 4.4mV RC...
 
Hello. Does anyone know what laser assembly was used in the mk1 alto CD players? Or if they were used in any other decks that I might pick up cheaply as a donor? Thanks
 
You must log in or register to reply here.


advertisement


Back
Top