I tried to build the Tubes4hifi SP14 preamp from their board and a few select parts but it is unacceptably noisy with a 400 watt solid state power amp with a 120Hz hum from an impossible to diagnose ground loop presumably. I've built five First Watt amps so I'm not an inexperienced builder but the SP14 has me flummoxed. There are quite a few posts by people who have run into the same problem with the SP14 or essentially identical designs from Glassware etc.. Because of the hum it is hard to tell whether or not it would be a good preamp if it was quiet.
Preamp Opinion
A couple of weeks ago, I asked for advice on my amp and preamp. Although I am sure that it could be improved, I have come to the conclusion that the Parasound A23 is the least of my problems. I also have a Parasound New Classic 2100 preamp, a Marantz 8600 CD player/streamer (which I also think doesn't need to be replaced), and Focal Aria 926 speakers. I did listen to advice I was given and am expecting a vintage McIntosh SL-1 sub to my system.
I am looking at a few used preamps and wanted to get your opinions on them since the only one I have heard is the Adcom GFP-750 and that was years ago. My memory is that it had a very good sound to it. The other preamps I am considering are the Rotel RC-1572, Rogue RP-1, Coplant CTA 301 MKII, Bryston BP6, and Vincent SA-T7. Unfortunately, I have not heard any of them and don't have a location where I can. I tend to prefer a sound that is not too bright but provides a good clear soundstage and imaging. I have always owned solid state before and am a little leery of tube maintenance.
Thank you for your advice or observations about any of these preamps.
I am looking at a few used preamps and wanted to get your opinions on them since the only one I have heard is the Adcom GFP-750 and that was years ago. My memory is that it had a very good sound to it. The other preamps I am considering are the Rotel RC-1572, Rogue RP-1, Coplant CTA 301 MKII, Bryston BP6, and Vincent SA-T7. Unfortunately, I have not heard any of them and don't have a location where I can. I tend to prefer a sound that is not too bright but provides a good clear soundstage and imaging. I have always owned solid state before and am a little leery of tube maintenance.
Thank you for your advice or observations about any of these preamps.