Just received this ARC LS7 pre amp and taken a look inside. The person that recapped it was definetly on a mission.....why so many, what are they doing, big cluster of caps to the left???? Looks like it's had a new power lead as well. So many questions!
It will be a few weeks before I can fire it up and hear what it sounds like. Are the Brimar valves any good? not really after warm, more detail and punch would be my preference. Picture of a stock LS7 included.
It will be a few weeks before I can fire it up and hear what it sounds like. Are the Brimar valves any good? not really after warm, more detail and punch would be my preference. Picture of a stock LS7 included.
Attachments
Looks like they were bypassing the electrolytics in the power supply with multiple film caps, as well as replacing the original coupling caps with Hovlands, also bypassed. Ostensibly this is to improve the high-frequency performance of the caps.
Yes, Brimar's are nice tubes. If you want detail and punch, the Hovlands should give you plenty of that. They didn't call them "Fast Caps" for nothing. ;-) They're certainly not "warm," in my experience.
It's a pretty nice job - I wouldn't change anything before a careful audition.
I'll let the real connaisseurs chime in re. the Brimar. AFAIK, Philips introduced the ECC88 in 1957, and STC sold Brimar to Thorn in 1960; I doubt that was time enough to tool up for a new tube among the chaos of a merger.
I'll let the real connaisseurs chime in re. the Brimar. AFAIK, Philips introduced the ECC88 in 1957, and STC sold Brimar to Thorn in 1960; I doubt that was time enough to tool up for a new tube among the chaos of a merger.
It looks likes good workmanship to me as well. I'd also agree that you should give it a serious listen before making any decisions. As always there are at least 2 schools of thought at each end of the spectrum, leave it stock vs modify. I tend to fall into the latter category, IMO the Hovland capacitors bypassing the electrolytics should be an improvement, the replacement of the MIT and Wonder Caps could come down to which sound you prefer. Adding some tube dampers wouldn't hurt, I'd also do a cleanup of the interior. I wouldn't obsess over the power cord.
Thanks everyone for the input. Good to know the Hovland caps are supposed to be a bit more dynamic/fast. I agree that the work carried out looks very neat and in good order, any tips for cleaning the inside up and de-dusting?
I'll be using an ARC D130 power amp, also just arrived and not tested yet, going into an old pair of Sonus Faber Concertinos'. I Should know in a few days how it all gels together 🥺
I'll be using an ARC D130 power amp, also just arrived and not tested yet, going into an old pair of Sonus Faber Concertinos'. I Should know in a few days how it all gels together 🥺
Ensure the unit is not plugged in and main filter capacitors have had time to discharge.
Start with a light cautious vacuuming. If that isn't adequate you can loosen up the dirt with a Qtip or soft tooth brush, vacuum as required. If needed sparingly use a light solvent applied directly to the Qtip, Windex or Fantastic often works, if its worse you can alway use flux remover, agitate with a Qtip or similar and clean up the residue.
I'm sure others have their own methods but this works for me.
Note: use extreme caution around the tubes, I try not to touch them with bare hands. If you use solvent on the boards be careful that you don't destroy the labelling on the tubes. I tend to leave the tubes in place until I get all of the dust and/or debris out to avoid getting any in the tube sockets. I clean the tubes with a soft clean cloth, no solvent. Check the pins for oxidation, either way seat and reseat them a few times in the socket.
Good luck and happy listening.
Start with a light cautious vacuuming. If that isn't adequate you can loosen up the dirt with a Qtip or soft tooth brush, vacuum as required. If needed sparingly use a light solvent applied directly to the Qtip, Windex or Fantastic often works, if its worse you can alway use flux remover, agitate with a Qtip or similar and clean up the residue.
I'm sure others have their own methods but this works for me.
Note: use extreme caution around the tubes, I try not to touch them with bare hands. If you use solvent on the boards be careful that you don't destroy the labelling on the tubes. I tend to leave the tubes in place until I get all of the dust and/or debris out to avoid getting any in the tube sockets. I clean the tubes with a soft clean cloth, no solvent. Check the pins for oxidation, either way seat and reseat them a few times in the socket.
Good luck and happy listening.