ah.
Ok. I've had the Variac for some time.
Really glad you nudged me to use it.
Talking about getting set in my ways.
Ok, Tomorrow we start anew.
Thanks
Ok. I've had the Variac for some time.
Really glad you nudged me to use it.
Talking about getting set in my ways.
Ok, Tomorrow we start anew.
Thanks
@ChrisM91, congratulations on a beautiful, clean build!
but why does the right channel look like it's either built with components mounted on the wrong side if that's even possible or you somehow ended up with 2 left channels?
Why are your mosfets at the top on the right channel?
If you refer to the picture in the first post - 6L6 has a shot of both boards - one says Channel A and the other should say Channel B.
but why does the right channel look like it's either built with components mounted on the wrong side if that's even possible or you somehow ended up with 2 left channels?
Why are your mosfets at the top on the right channel?
If you refer to the picture in the first post - 6L6 has a shot of both boards - one says Channel A and the other should say Channel B.
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Send me a PM. When the current lock down is lifted I have a set of store boards you can have.
Thank you for the generous offer! The store actually sent me a new set after I informed them of their error. Debating whether to built the new board or not...is it worth desoldering the precious FETs and transformer...Amp sounds and works great, listening right now in fact!
If the 'sinks and power fets are about the same temp between the 2 channels, no reason to change
The F6 is not a great heat producer.
If it's working well, I would close it up so you can't see the "mistake" and hold on to the boards for that secong F6 you know you always wanted. 😀
AMP finished and works perfectly
Thanks to the forum and all people who helped me the work is completed.
Absolutely no issue even for the final tuning, thanks to the methodology regarding pots settings before power up (I mean setting one to ground and the other to negative rail); need to turn and turn and turn clockwise until the good value is reached ont the DMM, then power up the amp and wait some minutes before turning Bias pot counterclockwise to reach 500 mV. Then wait at least 10 minutes to reach the good temp. Any action on one pot modifies the other setting. As said, just be patient.
At the end, the amp is not very warm.
Sound is perfect. No hum, not any noise.
Actual config uses a Cambridge DAC, Nutube preamp now connected to the F6.
FYI I have in project to build a guide in french. 😀
Thanks to the forum and all people who helped me the work is completed.Absolutely no issue even for the final tuning, thanks to the methodology regarding pots settings before power up (I mean setting one to ground and the other to negative rail); need to turn and turn and turn clockwise until the good value is reached ont the DMM, then power up the amp and wait some minutes before turning Bias pot counterclockwise to reach 500 mV. Then wait at least 10 minutes to reach the good temp. Any action on one pot modifies the other setting. As said, just be patient.
At the end, the amp is not very warm.
Sound is perfect. No hum, not any noise.
Actual config uses a Cambridge DAC, Nutube preamp now connected to the F6.
FYI I have in project to build a guide in french. 😀
Attachments
Brought home a pair of Anthony Gallo 3.1 speakers yesterday and oh man does the F6 sound sweet.
I was a little worried that the 25W/pc F6 would have a hard time driving these 88dB speakers with their 10" woofers but they sound great, soundstage and imaging is top notch. The F6 delivers yet again!
I was a little worried that the 25W/pc F6 would have a hard time driving these 88dB speakers with their 10" woofers but they sound great, soundstage and imaging is top notch. The F6 delivers yet again!
And another F6 is up and playing wonderful music.
My thanks to ZenMod and everyone who has posted to the forum and helped me thru the wrong turns.
I learned more about trimpots, making sure to know where they are set before biasing and about Jfets.
I've started listening driving my Falcon LS3/5A kit speakers. A couple of observations:
Biggest soundstage I've heard from these speakers,
I had to turn down my sub, and
the sound is deep and rich.
Very much worth the effort.
My thanks to ZenMod and everyone who has posted to the forum and helped me thru the wrong turns.
I learned more about trimpots, making sure to know where they are set before biasing and about Jfets.
I've started listening driving my Falcon LS3/5A kit speakers. A couple of observations:
Biggest soundstage I've heard from these speakers,
I had to turn down my sub, and
the sound is deep and rich.
Very much worth the effort.
Attachments
Yipeeee. The F6 is up and playing music. Bias at 0.500 volts. I'm using a BDP 105d without a preamp. My speakers are stock block Martin King OBs with the Jordans and 18-inch Goldwood woofers. See attached. The upper and mid-ranges sound good, clear, and tight. The low end is fairly weak. I know, OBs are supposed to have weaker base. However, my PP6A3 amps provided stronger base.
The F6 has a frequency response that goes down to the basement. Could the lack of a preamp be the issue? Maybe my speakers are not a good match for the F6. As always, your comments would be appreciated.
.
The F6 has a frequency response that goes down to the basement. Could the lack of a preamp be the issue? Maybe my speakers are not a good match for the F6. As always, your comments would be appreciated.
.
Attachments
![20210417_170720[1].jpg](/community/data/attachments/862/862356-0658f3d74f1c0a36c06f50af862675a9.jpg?hash=Bljz108cCj)
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try inserting some low value resistor in line with one speaker wire
tube amp is certainly having lower damping factor, so helping with bass
start with, say, 0R22/3W and go up; leave what's best for your ears
tube amp is certainly having lower damping factor, so helping with bass
start with, say, 0R22/3W and go up; leave what's best for your ears
Thank you ZM, I got the resistors to adjust the damping factor. The 0R33 mills brought the bass up to where I like it. Next, I cranked up the bias to 0.550 V. In the process I got a spark from the left channel 0R47 resistor to my shielded meter probe. Now I have a persistent 120Hz? hum on the left channel. The bias and offset remain correct on both channels at 0.550 V. I don't have a scope to snoop for the hum. Any ideas? HeyBill
Check that your rectifiers are still OK. Maybe one or 2 diodes in the rectifiers went kaboom.
Monolithic bridge rectifiers look good. I'll keep poking around. Hopefully without further sparks.
