Well, it is the fifth anniversary of the last posting on the A-7 amp,
And yes inded, it was a Heath A-7, as shown here:
http://www.kta-hifi.net/projects/amp_page/a7amp/a7.htm
The Heathkit A-7 amplifier was produced over a relatively long span of time from about 1952 until the early 1960's. Four versions are known to exist including the A-7 thru A-7D. The smallish chassis was finished in a gray hammer tone enamel, and had a detachable front plate with the model designation and control markings screened on it. (This may have been to facilitate cabinet mounting. The chassis has no provisions for a bottom plate or cage. Some models have phono amplifiers and some do not. The tube complement is one 12SL7 (phono version only), one 12SQ7 utilized as a tone control amplifier, a 12SN7 as a voltage amplifier, and cathodyne phase inverter, and a pair of cathode biased 12A6/VT134A beam power pentodes in an ultra-linear connection. Output power is estimated at about 7 watts, and although the original output tubes are metal, the glass 12A6GT can be substituted. The transformers are reputedly of Chicago manufacture, but I had problems with the power transformer in the older of the two units.
Schematic can be found here (PDF format):
http://www.nostalgickitscentral.com/hea ... ma_a7e.pdf
Take note that the Heathkit A7 runs the 12A6S really
hot, with a B+ of 390V
And in gif format:
http://www.audiophool.cjb.net/Schem_A/Heath_A7.gif
/ed B (looking for something useful to do with a gaggle of 12A6s I have laying around)