jose

I did not remember that my input board bridges the Cold channel with ground when I select the a SE channel. So that's not the problem.

Thanks for the answer boys Yes, I also think that having SE and balanced inputs brings a lot of versatility. In my Stax amps I always bypass the cold channel (I use input selectors with relés) in SE inputs, but in the dynahi I hadn't through necessary... remember that I heard the crackling noise yesterday and I have this amp for a long time. For the outputs, SE and balanced is also necessary by the different types of headphones that I have. Yes, I understand that it's a waste of energy and that even results in the longevity of the components but we aren't talking about using a Grado. In my case use my Dynahi with high impedance and/or an disgusting sensitivity.

Thanks spritzer. I'm working on it now. Let me check.

Because at the moment I haven't had problems with that. If it's the problem it's easy to solve but I doubt it's my problem. As for the output device (hope you like it more...), you're right I'm wrong they aren't mosfet.

Yesterday I was listening to my amp and I noticed a small sound coming from both channels, it's not constant and it's not perceived while listening music. It's a sound like "fried". I was listening SE input and SE output and I don't bridge the cold input to ground. I have been taking some measurements and BIAS is symmetric on both sides; 750/760 mVolt on R channel and 720/735 mVolt on L channel. On the contrary, offset drift a lot and I've never been able to keep it on 0 volt. It's always between -100~40 mVolt and 120~60 mVolt (without servo). With servo, the offset never exceed 20 mVolt. It has always seemed to me that Mosfets run too hot for an on-board assembly (Mosfet reach 90°) although I know that the maximum temperature is 150° but even so, components and the PCB also get very hot. I'm not sure where to start since I've changed the THAT and OPAs too and I still have the same noise. Can Mosfet be damaged? Or can the problem be elsewhere? Thanks

I always use this on trafo lines, from EIC to trafo. Usually I use a solid state relay and you can use T2 soft start design for do it.

I wouldn't put anything on the out put. To have a soft start I put a relay in the trafo or HV part (between amp and PSU). With 10 seconds is sufficient for the heating filaments to have some temperature.

Eric Johnson "Venus Isle"

Hum problems are a b***h. You only need patience. My SRX-P is dead silent now but I needed weeks of work to find the cause of the problem. Basically trial and error. Edit: Laowei put this layout on "Technical Assistance/Advice Thread" maybe It can help you too.

I recommended the new Tung-sol 6SN7GTB

Porcupine tree "in absentia" with my F5ha and HD600

Flat stage with final Sprint [emoji23] [emoji23] [emoji23] :

Yes, I guess that on eBay you can find some PCB, but I only use a KBPC5010 bridge diode with a R10 as Nelson Pass recomends. My ground way : Psu Ground to Star grounding (before Bridge diode) Amp Ground (Amp has G on LV and HV, really is the same plane so I only use one of them) to Star grounding (before Bridge diode) or PSU Ground. Input rca (insulate)/XLR to Volume Pot Volume Pot (insulate) to Amp. Star grounding (diode/resistor/cap) to chasis Transformer shield wire to chasis (On the same place where you put the star Grounding) Earth ground (plug) to chasis. (On the same place where you put the star Grounding) Very important: If you are using an unbalanced input, you must bring the "cold" channel to ground.

Sorry, English is not my language. If you take a look at my photos, you can see that I separated as possible the heating lead to the rest. I did a star grounding with a simple loop breaker (with a bridge diode) I'm sure that you know this but I recommend you read this http://sound.whsites.net/earthing.htm

BH Psu vs KGGR ? This can be a good topic to discuss and learning.

If it can help you; I had similar problems with 6 step and a f@$k Hum. I changed the ecc81 quads until I found a perfect mach quad at the same time, I separated the AC lines and did a ground loop breaker. Now my amp is absolutely silent and the different between triodes is around 3~8 volt.

Happy birthday

Oh guys, my Dl-103 and I love this vinyl: I have the same edition (rhino label)

Happy birthday!

Porno [emoji41] [emoji41] [emoji41] [emoji41] [emoji41]

happy birthday!!!!

Ummm I'm interested. Only for 400v Psu? I'm burning some EL34 and I recognise that the sound now is much better so I'm happy however, I wouldn't mind testing your mod.

Happy birthday!

It´s a nice ride. Here, I use 34/50 compact with 11/32 or 36/52 compact with 11/28 but my friends use a 34/50 with 11/28.