Upgrade my 8000A where is a good place to start

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Hi,

In the 8000A the MC stage and RIAA phono stage run down the extreme left,
the regulator transistors are bolted to the left chassis and it gets quite warm.
there is no seperate headphone amplifier, usual resistors from the output.

rgds, sreten.
 
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Still thinking...
I know Hughs designs are highly regarded... although I haven't listened to any myself... but I know Hugh seeks the same kind of sound that I like and his NAKSA 70 watt amp, well lets just say it has all the right ingredients.
 
I think that a good quality kit will set me down the right track, but this wont be for a while yet, got to save my pennies.
Here are my loudspeakers, in case any of you lot are interested, they are Amazing, warm detailed, and very powerful, had to wad the ports, too much bass in my small living room.
Buprj0wBmkKGrHqMOKjUEvL60NPYsBMBPOI3U2_12.jpg
 
They are QLN's from the early 90's, picked them up about 2 months ago i believe they are in yew. QLN reference they are called. My ones that were built by a cab maker are unfortunately with the guy that paid for them :-( they were T-line design, and rather large, lead lined and weighed about 15 stones........each!!!!!!!
 
Hi,

Instead of wadding the ports try lining them with porous foam, depending
on port size around 5mm to 1cm thick. cut a rectangle 3 x diameter and
the port length. Put this in the ports, they will be self supporting.

This will detune the ports, tightening and extending bass, usually works.
Also damps turbulence and port resonances.

rgds, sreten.
 
Last edited:
Hi,

Instead of wadding the ports try lining them with porous foam, depending
on port size around 5mm to 1cm thick. cut a rectangle 3 x diameter and
the port length. Put this in the ports, they will be self supporting.

This will detune the ports, tightening and extending bass, usually works.
Also damps turbulence and port resonances.

rgds, sreten.

that is brilliant, going to try that, as the bass is a little muddy still, cheers:D
 
Hi,

I have a 8000A with same issues until it was recapped (no other changes). You can see the resultant at MyOldVintageHifi: Audiolab 8000A (serial number with 'F')

I did the following in my 8000A.

The "harshness" reported can be address by the location of the caps displaced by the 2 OSCON caps in the pix.

The bass be improved by replacing the Evox with equivalent values of Wima's in the power amp section (just above the OSCON). The pre-amp section require some of the poly caps to be replaced, especially the 22pf Evox with 33pf silver mica's.

Rest of the other other caps replaced produce minor incremental improvements (to my ears) which adds up in the overall presentation.
 
My amps serial number has a 'B' in it. I am just comparing the two now as I have my amp with the lid off on my lap. It looks very similar to the one that you show.
I am considering changing the opamp as well, any experience with that.
I have some 2604 op amps, I am just checking that they both (the one in the amp at the moment) compatable.
 
not another that won't read!

Indeed it is, sorry blonde moment there :eek:
I am not sure what exaclty if anything to do to this amp. I might, if its worth it, replace the caps in the pre-amp section, and leave the power amp section, as want something more meaty to drive my large QLN reference speakers.
I used to have a meridian 557 power amp (before I had my kiddies, bless them) but know that is a long way off. Would love to know if I can build or get something that is near to that sound and power. I am not into loud thumping music, but believe that the headroom it gave meant it drove the speakers that I had at the time with ease. I also used to own a Quad 405 mark II power amp from the 80s, thats was lllooooverllllyyy, but that has long gone.:(
Not sure really what to do at the moment. One thing I do know, it will be a while before I can do anything, with christmas fast approaching :eek:
 
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