I built your ST70 kit in August '09 with cap upgrades and love it !! I'm using a McIntosh C28 pre-amp. Everything was great until the volume control went bad on the C28. I sent it to Terry Dewick (well known McIntosh specialist) to replace it. Unfortunately the only control now available with a power switch isn't the electrical equivelant to the original. So now when set to minimum volume it plays too loud for night listening. I have the top panel main output pots set at minimum. I really don't want to change the ST70 board to the low gain version because it works fine with other pre-amps I have used (and I already changed the 12AT7's to the Valve Electronics Mullards). I know you advised changing the center tube to a 12AU7 in this forum but I would rather leave the ST70 alone if possible as there is nothing wrong with it. I've been advised to try inline RCA attenuators between the pre-amp and power amp. I know there are variable and fixed value ones made. Would you recommend this and if so any spacific ones you like ? Thanks, Chuck
2 posters
Question for Bob
Bob Latino- Admin
- Posts : 3277
Join date : 2008-11-26
Location : Massachusetts
hfh wrote:I built your ST70 kit in August '09 with cap upgrades and love it !! I'm using a McIntosh C28 pre-amp. Everything was great until the volume control went bad on the C28. I sent it to Terry Dewick (well known McIntosh specialist) to replace it. Unfortunately the only control now available with a power switch isn't the electrical equivelant to the original. So now when set to minimum volume it plays too loud for night listening. I have the top panel main output pots set at minimum. I really don't want to change the ST70 board to the low gain version because it works fine with other pre-amps I have used (and I already changed the 12AT7's to the Valve Electronics Mullards). I know you advised changing the center tube to a 12AU7 in this forum but I would rather leave the ST70 alone if possible as there is nothing wrong with it. I've been advised to try inline RCA attenuators between the pre-amp and power amp. I know there are variable and fixed value ones made. Would you recommend this and if so any spacific ones you like ? Thanks, Chuck
Hi Chuck,
I have heard of a few people using RCA inline attenuators in cases where their preamp is set up to have the volume come on too quickly. On the VTA ST-70 and ST-120 you would probably be better off placing the attenuators on the back of the preamp because the ST-70's input jacks are fairly close together. Parts Express sells a number of RCA attenuators at the link below. Probably either a 3 dB or 6 dB attenuator would work best in your situation.
Parts Express RCA attenuators
Bob
hfh- Posts : 2
Join date : 2009-12-18
Thanks Bob, Just ordered a pair of Harrison Labs 6db attenuators. Chuck
Similar topics
