![single 6aq5 tube amp single 6aq5 tube amp](https://www.seventransistorlabs.com/tmoranwms/Circuits/Small_SE_Amp.gif)
The heater circuit also has high currents but those currents are isolated from ground and don't pose a ground noise problem. If there was feedback, grounding of the speaker jacks could be an issue. In the speaker circuit of this amp, the high current is enclosed loop and does not flow through ground because the ground wire of the OT goes directly to the speaker jacks. Unless the gain is very high, they cause no problem. Signals in the preamp are very low current and don't cause much ground noise. Differential circuits such as between the phase inverter and the power tubes or between the power tubes and the output transformer can reject a difference in grounds to a large degree.
SINGLE 6AQ5 TUBE AMP SERIES
When you try to connect single ended signals between two circuits, the signal current must return thru ground and any difference between the grounds appears as a noisy voltage in series with the signal. Note that as far as the signal is concerned, B+ and the local filter cap are considered as grounds.
![single 6aq5 tube amp single 6aq5 tube amp](https://getaudio.eu/wp-content/uploads/2017/06/4w_TU-8150_6V6.jpg)
Ground noise is created when current from one circuit creates a voltage that appears as a voltage difference between two grounds. When current flows through that resistance, a voltage is created. In the real world, every wire and even the chassis has a finite resistance. Actually, the way grounds were laid out originally would probably work well enough but if the hum is objectionable, a nightmare to fix.
![single 6aq5 tube amp single 6aq5 tube amp](https://reverb-res.cloudinary.com/image/upload/s--E2QCItD3--/a_exif,c_limit,f_auto,fl_progressive,h_620,q_75,w_620/v1459822221/wyz47y5oieg5wps53h8n.jpg)
Multiple ground lugs on a transformer bolt isn't a good way of doing that, sadly. Star grounding can work if you can connect all the wires together at one point.
![single 6aq5 tube amp single 6aq5 tube amp](https://ae01.alicdn.com/kf/H0e3644479ae24f31b7d4620a4bc92d27X/130W-ST-6P1PP-6AQ5-6V6-EL84-Push-Pull-Single-Ended-Tube-Amplifier-Power-Transformer-Output-250V.jpg)
I've gotten so obsessive/compulsive about grounds, it's the first thing I do when laying out an amp. If I could get permission, I'd use one of his illustrations here to demonstrate what I have tried to do in the layout. Kevin O'Connor devotes at least a whole chapter to the subject in one of his books. Does it matter? Does it depend on the power transformer? In my case, should I use pin 2 as the tape recorder did, or should I use pin 8 as the 5e3 designs do? All the 5e3 layouts I see take it from pin 8. The tape recorder takes its B+ voltage from pin 2 of the 5圓 rectifier tube. run the wire that would go to pin 5 of a 6V6, to both pins 1 and 7 of the 6AQ5)? Can use either 1 or 7, or do I have to connect the two, externally. I also have a few general questions about the project that I’d appreciate some help with.įirst, the data sheet for the 6AQ5 shows pins 1 and 7 being the grid. My hope is that some of you experts will take a look and let me know if I’ve screwed something up, or if you see any problems with the plan. I've also uploaded the original schematic for the tape recorder. I’ve uploaded a copy of my end result (I also redrew the output jack arrangement to match my OT). I have used the 5e3 layout diagram from Triode Electronics as a starting point and redrawn the power tube portion for 6AQ5 tubes instead of 6V6 tubes. I am working on converting a 6AQ5 reel to reel tape recorder circuit to a 5e3-type guitar amp.