Studio Projects T3 Original Like New, Upgraded input output cap 1000pf Polystyrene $500

[Lelandletham]

Original Studio Projects T3 with upgraded NOS Mallory 1uf 400v 1% beast output cap under transformer photos below was a SNUG fit but big difference, caps and switched to 1000pf polystyrene, also mial polystyrene 4700pf cap. and I can add additional cap swaps if you’d like too. Has a vintage Jan 12at7 in it and I’ll throw in an extra tube 12at7 or 12ay7 6072 your choice. The few listed I’ve seen are 400-680 without mods, feel free to ask any questions. When I get home I’ll take photos of the circuit. Comes with power supply obviously, thanks! $500 mic is like just has the new with the cap updates

 

[Emmathom]

Hi @Lelandletham

Original Studio Projects T3 with upgraded NOS Mallory 1uf 400v 1% beast output cap under transformer photos below was a SNUG fit but big difference, caps and switched to 1000pf polystyrene, also mial polystyrene 4700pf cap. and I can add additional cap swaps if you’d like too. Has a vintage Jan 12at7 in it and I’ll throw in an extra tube 12at7 or 12ay7 6072 your choice. The few listed I’ve seen are 400-680 without mods, feel free to ask any questions. When I get home I’ll take photos of the circuit. Comes with power supply obviously, thanks! $500 mic is like just has the new with the cap updates

Just bought a T3 for cheap because it does not have its PSU. So I built one with some mods.
First, HV is 120v (instead of 200v) and heater is elevated. A schematic below speaks more than words.
1,5uF@400v filtering (C1) has been changed for a Nichicon. C2 (couplinig cap) is a MKP Audiophiler 1uF@400v
I have got a NOS Sylvania 6072.
I'm now waiting for delivery of a 7 pins XLR chassis for the PSU so I did not yet made tests for now...

 

[micolas]

Hi @Lelandletham

Just bought a T3 for cheap because it does not have its PSU. So I built one with some mods.
First, HV is 120v (instead of 200v) and heater is elevated. A schematic below speaks more than words.
1,5uF@400v filtering (C1) has been changed for a Nichicon. C2 (couplinig cap) is a MKP Audiophiler 1uF@400v
I have got a NOS Sylvania 6072.
I'm now waiting for delivery of a 7 pins XLR chassis for the PSU so I did not yet made tests for now...

Hi @Emmathom!
The SP T3 is an interesting microphone, a good platform for mods.
It seems that the capsule is the one used in the C series, a highly appreciated 797. I use it with great results on acoustic guitar. Others, in deemphasis circuits swear by a tone in the 87 range. People report that an upgrade to a better NOS 6072/12AY7 tube,Telefunken,GE,RCA, tames the harshness from the top end.
And Sylvania is an obvious improvement.
Others prefer to replace the stock K67 with a CK12, some even test different brands of transformers.
We are waiting for good news.
Good luck!

 

[Emmathom]

Hi !

I got my 7 pins XLR (at last !!! after waiting for 2 months) and finished the wiring of the SP TB1.

I've got 123v before the 6,8KΩ R1 and 114v after which implies a 1,45mA for HV consumption and 92v on plate.
Cathode voltage is 910mV. Polar. 62v on backplate.
Tube is a RFT 6072 NOS

Quick voice test : output level as other static mics (but less than my SC1100 & 6AK5) / no noise nor hum / frequency response : nothing special to report > good result

Done. Must use them in real situation (music recording).
Now... next project

 

[Emmathom]

EDIT : I've added a 150pF polystyren from plate to ground to dim some highs.
Thanks to @micolas & @rock soderstrom for the tip !
New and final schem. below