How I made head direct out of Studers

tony ky ma

Industry Expert
Aug 22, 2010
Whitby Ontario Canada
Out broad amp is a kind of up grade of tape recorder but how to connect to the head is a question. closer is better too far away (too long cable or weirs) will create problems. here what I did with A80RC A810 and PR99
In A80RC very simple use two extra card (pictures) to replace repro card direct plug to mother broad will do, and can just put repro card back for comparison stock sound
A810 can not directly connect to the head pins because there has a metal tube protection in what we can do is from the in put of it's pre pre amp to add a switch in this point will help back to the stock sound
I replaced the record head to a 4 track re pro head of a PR99 deck that I can listen some pre recorded 4 track tape and add switch for back to stock in 2 track only but no more recording of this machine
tony ma



Mar 12, 2017
Mine is a homemade simple direct wiring from tape block to external tape pre about 3 feet. It works better than what I had before which routed through board and switches inside the machine. Only now I cannot switch back to playing with original repro card.

Routing from here ...

C1D5BBB4-709B-4219-B843-0E921189432D.jpeg here.


Likes: Folsom


Oct 26, 2015
Eastern WA
I wonder if it bypasses some important EQing in the machine... I'm not sure it's advisable till I see otherwise notation.
May 25, 2010
SF Bay Area
Many of us use external prepros with our machines. Not sure what you are asking. Tony did an internal connection while Tang did a direct external connection. I've seen both.

For Folsom, the external prepros are designed to bypass all the playback electronics in a machine, including the EQs provided. They have all the necessary circuitry for the EQ's. Mine (a Doshi 3.0) has NAB and IEC (CCIR) and even AES (for 30ips).


Mike Lavigne

Member Sponsor & WBF Founding Member
Apr 25, 2010
2 of my 3 Studer A-820's have direct-out head switches for use with my King Cello tape repro output electronics. my King Cello can be adjusted for different heads if i remove the top plate. but i never do that. September i'm sending my King Cello back to Charles King to have pots, meters, and finer gain adjustments installed so i can dial it in better.

top pic is my 1/2" bottom pic is my 1/4", both with direct out switches. the switches are on the back side of the head block housing. this allows me to use the stock output for either machine when i'm doing dubs. i prefer all stock (all 3 Studers have the transformerless audio output cards) signal path for that. playback gives the advantage to the King Cello for a number of reasons.


May 30, 2010
I have a direct connection to the Bottlehead preamplfier, but I know that Fred Thal pre-preamplifier is the proper way to go ... As far as I know Nick Doshi also uses an IC buffer in his tape preamplfier, probably he could also design something with a similar topology.

Jan 18, 2012
Drobak Norway
even connecting wires to R47 on A80 reprocards will give you a possibility to experiment with different buffer amps e.g tube,. while keeping onboard eq....
much easier and a possible first step to investigate if you want to do it all out
I ended up keeping my MTSL rebuilt onboard reproboards....
Last edited:

About us

  • What’s Best Forum is THE forum for high end audio, product reviews, advice and sharing experiences on the best of everything else. A place where audiophiles and audio companies discuss existing and new audio products, music servers, music streamers and computer audio, digital to audio convertors (DACS), turntables, phono stages, cartridges, reel to reel, speakers, headphones, tube amplifiers and solid state amplification. Founded in 2010 What's Best Forum invites intelligent and courteous people of all interests and backgrounds to describe and discuss the best of everything. From beginners to life-long hobbyists to industry professionals we enjoy learning about new things and meeting new people and participating in spirited debates.

Quick Navigation

User Menu

Steve Williams
Site Founder | Site Owner | Administrator
Ron Resnick
Site Co-Owner | Administrator
Julian (The Fixer)
Website Build | Marketing Managersing