Originally I was looking to build something like the AirTight amp. I know the transformers wont be the same etc. I will look at the pictures and trace the schematic myself.
Nope not taking the quiz. I have nothing to prove. Yes most of the resistors i use for my amps and stuff don't have color codes and have the values printed on.
Thanks to those that did help me.
I will not be responding anymore to this thread.
Nope not taking the quiz. I have nothing to prove. Yes most of the resistors i use for my amps and stuff don't have color codes and have the values printed on.
Thanks to those that did help me.
I will not be responding anymore to this thread.
sorry... tired of the crap. Its all very petty. Just trying to get some input and feedback on stuff. plus i will work on this by myself. 😉
I think the right question is “why?”
1- for the purpose of repair?
2- with the aim of creating a “perfect” clone?
NO....... 12ax7 in parallel.
3- with the aim of cloning the schematic without the specific information of the PT and OPTs?
Brown Black Red Gold 1K 12AX7 x 2 SRPP very simple circuit and a 600 ohm cathode R on the KT88 and current is set , go look at the KT88 datasheet for Ultra Linear and from there you can determine the input voltage and operating point , ohms law will do the restJust wondering if there is a schematic of the Air Tight M101 floating around? I found some nice interior pics and could reverse engineer it if i had too.
Is it just a 12AX7 SRPP into a KT88 UL with some global feedback?
Thanks!!
Richard
Attachments
Hi, On closer inspection on another image I found the 12AX7 has parallel plates and cathodes / grids with a 100K Plate's resistor and probably a 1.2K cathode's resistor .
The B+276V and 146v on the parallel 12AX7 plates strapped together @ 1.3mA .
The B+276V and 146v on the parallel 12AX7 plates strapped together @ 1.3mA .
Sounds encouraging, and the transformers look beautiful. But it would be interesting to see actual measurements when you are able.
Try this , its a working circuit with Tamura F915 they max out at 70mA /560R cathode , but you can trim them back to 68mA / 8 watts UL
I dropped the final back to 65mA / 500R cathode R on the KT88 /6550
Here's the thing I used GE6550 and was happy with 65mA you will need to set and trim with a 10R resistor in parallel to the main 10watt resistor with whatever brand of KT88 or 6550 to set it as they tend to vary a bit from book value in circuit .
The Tamura give an excellent account of themselves in UL 8 watts , the original Tamura was discontinued which led to the M101 demise , but some time latter a limited range of Tamura were release including the F915A 5K with a UL tap , below picture with the others, I prefer these the Hashimoto I have used both the F913A Tamura and the Hashimoto H-20-3,5U with a SE300B driven by a E280F in triode and the Tamura is a little darker and fuller sounding in the lower mids and bass still nicely balanced with the upper mids and HF .
The Tamura are on ebay now .
I dropped the final back to 65mA / 500R cathode R on the KT88 /6550
Here's the thing I used GE6550 and was happy with 65mA you will need to set and trim with a 10R resistor in parallel to the main 10watt resistor with whatever brand of KT88 or 6550 to set it as they tend to vary a bit from book value in circuit .
The Tamura give an excellent account of themselves in UL 8 watts , the original Tamura was discontinued which led to the M101 demise , but some time latter a limited range of Tamura were release including the F915A 5K with a UL tap , below picture with the others, I prefer these the Hashimoto I have used both the F913A Tamura and the Hashimoto H-20-3,5U with a SE300B driven by a E280F in triode and the Tamura is a little darker and fuller sounding in the lower mids and bass still nicely balanced with the upper mids and HF .
The Tamura are on ebay now .
Attachments
- Home
- Amplifiers
- Tubes / Valves
- Air Tight M101 schematic?