What is the output power of this amp? I am driving the HE1000 V2 right now, not easy to drive and this amp is doing an excellent job of it!
Hi,
My MARSH amplifier with +-14V PSU can delivery about 2W @ 35 ohm (9V rms ) - and 1W of these 2W will be pure class A ( with 120mA bias per transistor) and then ir will switch to class AB
My MARSH amplifier with +-14V PSU can delivery about 2W @ 35 ohm (9V rms ) - and 1W of these 2W will be pure class A ( with 120mA bias per transistor) and then ir will switch to class AB
When acerbic critic Sheridan Whiteside slips on the front steps of a provincial Ohio businessman's home and breaks his hip, he and his entourage take over the house indefinitely.
I want in!
Rush
I only need refer you to the esteemed Dr. Marsh's photographic avatar which has a striking similarity to that of Monty Woolley.
"The Man Who Came to Dinner" is a holiday favorite of mine. 1942.
Monty Woolley, Cole Porter etc. were a bunch of Yale guys who had a great time together! The movie also stars Betty Davis.
How is the listening? Has some others' finished and ready to give listening impressions?
THx-RNMarsh
THx-RNMarsh
Have others been listening for any affects from different power supply designs?
I will use this for my HPA ---->
View attachment hpa_psu_sch (2).pdf
THx-RNMarsh
I will use this for my HPA ---->
View attachment hpa_psu_sch (2).pdf
THx-RNMarsh
Might want to install an RC noise filter between each zener reference diode and its output driver. I use those nifty 3-terminal Feedthru Caps that TDK makes for RF applications. Fortunately they sell feedthrus in values > 4 microfarads.
Parenthetical -- LT1210 wasn't around when Walt did the Audio Amateur "Regulators" article, i.e. 1995 -- it makes a good "rail driver" for PSRR measurement.
My friends in Bangkok, Thailand (Magnet Audio Tech) built this all out effort from the article in Linear Audio. Everything on one PCB. Fine workmanship.
THx-Richard
THx-Richard
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Richard -- did they include the headphone comp which was an integral component of the article?
fwiw - looks great!
jack
fwiw - looks great!
jack
The suggestions came after their layout. But they can change it fast anyway... thats just prototype.
NO! They didn't include HP Comp. :-( Maybe we should do it ourselves?
Shortly afterwards several people started playing with the idea and now there are some headphones that do it, I believe, semi-automatically.
I am listening with Senn. HD-800 phones now and they are 300 Ohm. These phones are really excellent.
-Richard
NO! They didn't include HP Comp. :-( Maybe we should do it ourselves?
Shortly afterwards several people started playing with the idea and now there are some headphones that do it, I believe, semi-automatically.
I am listening with Senn. HD-800 phones now and they are 300 Ohm. These phones are really excellent.
-Richard
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All my topologies are inherently linear, fast, wide bandwidth. Today, I got around to measuring the BW.
With the original transistors I tried, the BW = 5 MHz at -3 dBv
THx-RNMarsh
With the original transistors I tried, the BW = 5 MHz at -3 dBv
THx-RNMarsh
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Let's see, 5 MHz bandwidth at a gain of 4X (12 dB), is a GBW product of 20 MHz. Almost as good as the FET input opamps Jan Didden used in his 1995 Super Regulator, the AD817 (GBW= 50 MHz) and the AD825 (GBW= 41 MHz). We need to remember that the ICs are voltage feedback amplifiers but the headphone amp is a current feedback amplifier.
These chips cost about five dollars each if you pay extra for thru-hole packaging: Mouser link
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These chips cost about five dollars each if you pay extra for thru-hole packaging: Mouser link
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