Type: Posts; User: OldmanSRS
The Adcom GFA-555 collects the feedback signal from the speaker wire connection at the rear of the amp chassis. If the feedback sample point was extended to the speaker wire connection of the...
Interesting. Is the internal cabinet wiring at least as good as some of the jumpers you tested? What gives the bass more weight clarity and speed when the jumper is feeding the tweeter array?
Oh man. Those are piezo super-tweeters from Radio Shack.
I measured the electrical signal to each tweeter in the 1.2. The tweeter was in the circuit and the dB meter measured the voltage across the tweeter terminals. Not sure what this info is good for...
"You never know what's going to walk through that door"
I bi-amped the 1.2s. Made no difference. If you use identical amps the bass/treble ratio will remain stock. If your amps have different gains, it will change. Bottom line, not worth the effort for...
Since the MW's don't produce much of any sound below about 30 hz, the PR is doing that job. Seems reasonable the 1.2 could effectively drive an 18" PR if the cabinet size was adjusted for a lower...
Tone generator feeding the Adcom 555 and a power meter on the output set at 4 ohms to verify.
Here's what 10W of clean power and a 20Hz sine wave can do to the walls of your listening room :eek:
That's not happening. I added DC offset protection and on/off protection to both the 555s in this post.
By coupling cap do you mean signal passing though it between amplifier stages?
Please clarify. Are you saying not to change the stock film caps to good polypropolene film caps? If so, why?
I'm not looking at the schematic right now but if memory serves there are only 8 caps...
The 555II is also common ground.
The 555II version does not have user-adjustable DC offset. It has a servo feedback using an integrated circuit chip that self-adjusts DC offset when it's working as it should. Bias is...
My pleasure indeed. Nice getting to know you and hearing your 2BTL's.
I discovered there is a 555 schematic on the web that does not match the one in the service manual from HFE. My amp is the same version as the manual. My DC offset was 198mV on the left and 14mV on...
Unfortunately the GFA-555 has no adjustment for DC offset, only for bias. If DC offset is out of spec (40mV max, 20mV typical) a component has changed value. The input stage has a pair of...
Stock is 91 dB but with the low DCR inductor mod, I measured a 2dB sound pressure increase (as well as a 2dB voltage increase at the SDA MW) level below 120 hz. I read those damping links some time...
I had the Carver connected to a CD with no pre and it still sounded tubby and lazy. I will not dispute the power, Adcom vs Denon but with the 1.2s at 93 dB efficiency, 200W is more than adequate for...
A great amp, without breaking the budget is an Adcom GFA-555. You can find them for around $300 - 350 in great shape. The large power supply caps are expensive if they are bad but there is a very...
Fundamental improvements to mankind were made by men who didn't care what their peers thought.
OK, got it...Just wondering...The word chisel used in the same post as Polk's makes me very unsettled :eek:
Thanks for the info.
Looking at the Monitor 10A Peerless and the Monitor 10B SL-2000 XO circuits, they are identical except for a 0.5 Ohm difference in one resistor. Given the XO circuits are identical otherwise, what...