Hi, a friend would like to change summing amps in his Gelf 24/8 70's console. He told me there are 4 TL074s as a summing amps.
I was thinking about installing API 325 amps for summing and have some questions:
1. Does 325 have enough gain for 24 channels?
2. What is 425 combining network and do i need it?
3. Would you leave the old summing amps untouched and make external summing box connected to direct outs, inserts or groups (depends if pan is needed)? In my opinion it is better to leave such a mixer (it is well done, sounds&looks good, but wiring is a big mass) as it is if it's not really necessary to change things.
For now i don't have any schematics to show you, but i checked the input module, saw some pics and got informed about designs from that time, and i can say it is very simple. Input modules have transformer balanced inputs, amp part is TL074, eq MCI458 and so on. I'm not sure what output, aux, monitor..amps are, but it seems TL074s are used everywhere and are supported with transistors in some places. All switches, pots and specially faders seem to be of good quality.
I have one more question: i searched the whole internet to find informations about this or any other Gelf mixer, designers names, but with no luck. If anyone could help us out we would be very thankful. Same goes for summing.
Miha
I was thinking about installing API 325 amps for summing and have some questions:
1. Does 325 have enough gain for 24 channels?
2. What is 425 combining network and do i need it?
3. Would you leave the old summing amps untouched and make external summing box connected to direct outs, inserts or groups (depends if pan is needed)? In my opinion it is better to leave such a mixer (it is well done, sounds&looks good, but wiring is a big mass) as it is if it's not really necessary to change things.
For now i don't have any schematics to show you, but i checked the input module, saw some pics and got informed about designs from that time, and i can say it is very simple. Input modules have transformer balanced inputs, amp part is TL074, eq MCI458 and so on. I'm not sure what output, aux, monitor..amps are, but it seems TL074s are used everywhere and are supported with transistors in some places. All switches, pots and specially faders seem to be of good quality.
I have one more question: i searched the whole internet to find informations about this or any other Gelf mixer, designers names, but with no luck. If anyone could help us out we would be very thankful. Same goes for summing.
Miha