A simple recording setup of excellent quality

Signal path:


Grampian GR1/L, 25-50Ω ribbon mics Blumlein Pair - Sowter 3104, 1:20 stepup input transformer for each mic (3.9 Henries to 470 Henries) - Ferrograph series 6 electron tube or valve reel to reel recorder at 7.5 ips


The Blumlein pair should have been in the middle of the room.


A cover of Supertwister - Camel was played.


The number of active amplifying devices from the musical instruments captured in the room by the mics to the recording tape is 3 electron tubes only. And a similar number for playback from tape, electron tubes, if for example played back on a Ferrograph, or transistors if for example played on a Uher.


The electric bass was connected to an electron tube amplifier to possibly 4 full range speakers connected in series parallel combination, mounted on an open baffle.


A WLM organ (from Finland) was connected to a PCL86 single ended class A electron tube power amp. The amp schematic from the excellent French data book Radio Tubes. The output transformer was made by Hammond manufacturing in U.S. The speaker was a rotating vintage ALNICO magnet full range mounted on an open back small cabinet and hanged from the ceiling for free rotation or Doppler effect, (Pleiades speaker).


Acoustic drums.


The Sowter transformers were used to match the low output and impedance of the excellent Grampian ribbon mics to the 1 MΩ ECC83 mic input of the excellent Ferrograph series 6.


Creamy smooth sound, no hiss.


Tape running at 7.5 ips.


At the time the heads were 1/4 track.


It is great using the same technique in modern recorders.


For example:


Moving coil mic or ribbon mic - input trasformer - electron tube or JFET prepreamp - any recorder


See the Pleiades V series battery electron tube prepreamps or the Pleiades JFET K117 prepreamp.


At the time nothing was known for the membrane bass absorbing panels, (Pleiades broadband absorbers). Nothing was known about the influence of the input transformer primary inductance on adjusting for bass proximity effect. Nothing was known that mics can be fairly close and compensating for bass increase. This recording was payed back after all those years on a Uher 4200 with just one channel operating and with mono bridged HD-580 headphones. Not tested yet with speakers, it might not sound good due to excesive room sound. But this particular recording made before 2000 sounds balanced, clear and warm. Might or might not send ordinary analog multitrack 24 channel recording with console mixing (adding more correctly) (complex signal path) to the cleaners.