need help for my new amp: 6G6G driver & 807 SE - Page 4

Original Burnedfingers · 26th September 2012, 11:25 PM

So, add another gain stage?

pilovis · 08:29 PM

The amplifier is finished!

, the sounds is so great!

Wow, Wow, Wow

I did not use any feedback since I don't like it (it flattens the bandwidth).

pilovis · 08:33 PM

Quote:

Originally Posted by Original Burnedfingers

So, add another gain stage?

There is no need to add any extra gain stage, the gain is more than enough, tested!

.

pilovis · 10th October 2012, 05:50 AM

HJWeedon · 11:32 AM

Hi pilovis.

Beautiful assembly and great case. I have a couple of concerns though. I assume that the larger white transformer is the main line-power transformer, and the two black transformers are output transformers. If you connect large loudspeakers with good bass response, and you might hear more 50Hz hum in one channel than in the other that could be because the middle output transformer is mounted parallel to the line transformer. If you turn that transformer around 90 Degrees you will probably find that the hum is reduced.

A second comment is that I believe that the rectifier tube is too close to the power output tube 807. During operation the two tubes would heat each other up and may overheat the glass where they almost touch. Power-tubes like these should not be closer to each other than about 20mm.

Congratulations on a beautiful construction.

Hans J Weedon.

pilovis · 12:03 PM

Quote:

Originally Posted by HJWeedon

Hi pilovis.

Beautiful assembly and great case. I have a couple of concerns though. I assume that the larger white transformer is the main line-power transformer, and the two black transformers are output transformers. If you connect large loudspeakers with good bass response, and you might hear more 50Hz hum in one channel than in the other that could be because the middle output transformer is mounted parallel to the line transformer. If you turn that transformer around 90 Degrees you will probably find that the hum is reduced.

A second comment is that I believe that the rectifier tube is too close to the power output tube 807. During operation the two tubes would heat each other up and may overheat the glass where they almost touch. Power-tubes like these should not be closer to each other than about 20mm.

Congratulations on a beautiful construction.

Hans J Weedon.

Very good points!

I will add a small internal fan.
Fortunately, there is no udible hum.

This is the video I took with my small digital camera

:
807 tube Ultralinear Class A - Stereo Hi-Fi Amplifier - YouTube

and just another picture:

pilovis · 11th October 2012, 06:18 PM

I listened to this amplifier connected to a pair of huge Warfedale E90, 100 kilograms of speakers

Wow, It was amazing, at almost full volume (7+7W), the room was full of sound with no audible distortion and very good quality of sound!

Someone told me this amplifier wouldn't have enough gain, some other told me the penthode driver wouldn't have a good sound

.

No comments

Warfedale E90

pilovis · 11th October 2012, 06:56 PM

The trick of the gain is in the capacitor between the driver's screen grid and ground

9th October 2012, 08:21 PM	#32
pilovis diyAudio Member Join Date: Jan 2012 Location: Nizza Monferrato - Italy	The amplifier is finished! , the sounds is so great! Wow, Wow, Wow I did not use any feedback since I don't like it (it flattens the bandwidth). Last edited by pilovis; 9th October 2012 at 08:29 PM.

10th October 2012, 11:27 AM	#35
HJWeedon diyAudio Member Join Date: Sep 2005	Hi pilovis. Beautiful assembly and great case. I have a couple of concerns though. I assume that the larger white transformer is the main line-power transformer, and the two black transformers are output transformers. If you connect large loudspeakers with good bass response, and you might hear more 50Hz hum in one channel than in the other that could be because the middle output transformer is mounted parallel to the line transformer. If you turn that transformer around 90 Degrees you will probably find that the hum is reduced. A second comment is that I believe that the rectifier tube is too close to the power output tube 807. During operation the two tubes would heat each other up and may overheat the glass where they almost touch. Power-tubes like these should not be closer to each other than about 20mm. Congratulations on a beautiful construction. Hans J Weedon. Last edited by HJWeedon; 10th October 2012 at 11:32 AM.

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26th September 2012, 11:25 PM	#31
Original Burnedfingers diyAudio Member Join Date: Nov 2002	So, add another gain stage?

10th October 2012, 05:50 AM	#34
pilovis diyAudio Member Join Date: Jan 2012 Location: Nizza Monferrato - Italy

11th October 2012, 06:18 PM	#37
pilovis diyAudio Member Join Date: Jan 2012 Location: Nizza Monferrato - Italy	I listened to this amplifier connected to a pair of huge Warfedale E90, 100 kilograms of speakers Wow, It was amazing, at almost full volume (7+7W), the room was full of sound with no audible distortion and very good quality of sound! Someone told me this amplifier wouldn't have enough gain, some other told me the penthode driver wouldn't have a good sound . No comments Warfedale E90

11th October 2012, 06:56 PM	#38
pilovis diyAudio Member Join Date: Jan 2012 Location: Nizza Monferrato - Italy	The trick of the gain is in the capacitor between the driver's screen grid and ground