A good combination was 2 stages of K117 (4.7K all resistors, 2.6V) driving 2 stages of a 12AU7 Vb=12V or one stage of varymu EF183F triode connected Vb=6V. AN ATTENUATOR WAS CONNECTED AT THE OUTPUT (50K2 ALPS blue potentiometer).
So signal path was:
Grampian mic - Pleiades 1:30 2.2mH - K117 - K117 Vb=2.6V - EF183 Vb=6V Ra-g=3.9M Ra=1.5K - ALPS 50k - Realistic disco mixer as headphone amp - att pad - HD-580
Other variation was 2 maximised gain stages of K117 Vb=6V 33K 4.7K separated by 100K potentiometer
nice at 9% of pot, compressing at 16%, very loud dist on 26%
Need to try lower gain versions on K117 with 3.3K-3.8K 10K Vb=2.6V which are higher than 4.7K 4.7K
So signal path was:
Grampian mic - Pleiades 1:30 2.2mH - K117 - K117 Vb=2.6V - EF183 Vb=6V Ra-g=3.9M Ra=1.5K - ALPS 50k - Realistic disco mixer as headphone amp - att pad - HD-580
Other variation was 2 maximised gain stages of K117 Vb=6V 33K 4.7K separated by 100K potentiometer
nice at 9% of pot, compressing at 16%, very loud dist on 26%
Need to try lower gain versions on K117 with 3.3K-3.8K 10K Vb=2.6V which are higher than 4.7K 4.7K
No comments:
Post a Comment