You mentioned the Marantz 8B as a benchmark of sorts at about $3k. Others have suggested SET designs.
Have you considered other vintage amplifiers? There are several golden era EL34 tubes amps that compare favorably to what is available new (after suitable rebuild...)
Dynaco MK-IV (mono blocks)
1/2 of a ST70, as monoblock, but with the full power supply of the ST70, extra PS capacity addresses the main weakness of the ST70 design. Many agree that the amp sounds so much better than a ST70. And a rebuilt pr can be purchased for less than $1k if you are patient.
Pilot 264 (stereo basic amp)
Fisher X1000 (integrated amp)
Scott 272 and 296 (integrated amps)
Fisher 200 (mono blocks)
Fairchild 260 (mono blocks)
Acrosound Ultralinear II (mono blocks)
Leak 60 (stereo basic amp)
Cary 40m (mono blocks) and SLA70 (circa early 1990's)
Icon Audio Stereo 25 (new production)
While not EL34, many love the McIntosh MC30 monoblocks, and MC240 stereo amp.
I bring all of this up as an alternative. You will be surprised by the sound of any of the above amps, after a careful restoration. Cost for each should be around your benchmark cost or less (+/-). You will likely be able to resell for your costs should you dislike the sound, our find something better.
Just some thoughts.
Have you considered other vintage amplifiers? There are several golden era EL34 tubes amps that compare favorably to what is available new (after suitable rebuild...)
Dynaco MK-IV (mono blocks)
1/2 of a ST70, as monoblock, but with the full power supply of the ST70, extra PS capacity addresses the main weakness of the ST70 design. Many agree that the amp sounds so much better than a ST70. And a rebuilt pr can be purchased for less than $1k if you are patient.
Pilot 264 (stereo basic amp)
Fisher X1000 (integrated amp)
Scott 272 and 296 (integrated amps)
Fisher 200 (mono blocks)
Fairchild 260 (mono blocks)
Acrosound Ultralinear II (mono blocks)
Leak 60 (stereo basic amp)
Cary 40m (mono blocks) and SLA70 (circa early 1990's)
Icon Audio Stereo 25 (new production)
While not EL34, many love the McIntosh MC30 monoblocks, and MC240 stereo amp.
I bring all of this up as an alternative. You will be surprised by the sound of any of the above amps, after a careful restoration. Cost for each should be around your benchmark cost or less (+/-). You will likely be able to resell for your costs should you dislike the sound, our find something better.
Just some thoughts.