Søren

Thanks for the answers, I am quite happy with them. I was most thinking of the possibellity of a big difference in the crossover, but that seems not to be the case. billybob, thanks, but I am not really new to the forum. I was active here when also mobile homeless wrote...

I think the title says it all, it could be in the crossover, but do you know ?

Is this Jeffery? No, quite the opposite; it is Søren and I do not think that Jeffery has spent 50 years in Greenland, I would have heard about it. But your post was very subtle. Søren

It will probably be something like this: http://diyaudioprojects.com/Tubes/Junk-Box-Audio-Amp/ but in a little more simple version. It started as a simple project but became more complex as modifications arrived. To start I will make it triode connected, no NFB and also a few other things. ECC82 and EL84. Søren

In the last 20 years I have separated the first part of the PSU from the preamplifier which makes it easier to avoid hum and noise. The voltage is about 315V with only a few mA B+ and there are (small) fuses but it covers also the filaments. It works very well. Here in Burgundy and in Greenland where I spent 50 years the main voltage is 230V which gives a peak voltage of +-325V. So that is what you are dealing with using everyday household applicants, lamps and so on. If you are behaving reasonably it is not a problem. Again there will be fuses and a certain (unofficial) plug standard. I have a number of Tamura PP OPTs and I think they are too good not to be used. The amp which I have in mind should work at a B+ at about 215V. There is a little disclamer which is that in the best case it will take most of a year before I can realize it because all my audio equipment is in eastern Greenland so I have to wait for the ice to melt so much that a cargo ship can sail; the idea of sending khorns and OPTs as airmail is probably not so realistic... Søren

I disagree with you that long runs of B+ are a problem, here in the house there are many meters of 230VAC carrying wires around. Of course you should take care of plug standards so you do not mix them up, but you have to be careful in all cases if you are playing with tubes. The idea behind could be that it is the best to keep the relatively long distances at a high voltage and high impedance and then first at last transform it to the low consumer impedance. By the way, that is what the power plants do. Long time ago I saw on the net that a person had modified/repaired an amplifier on the working bench and for some reason was unable to test it as it was in parts. So he placed the OPT near the speaker for other reasons and was surprised that it sounded better than normally. My main surprise here is that nobody seems to be curious to try it, everybody says that it is a bad idea, but not why (except the B+). A possible explanation if it is better could be that the loudspeaker cable such to say disappears. Søren

I have often thought that there would be advantages in having the OPT near the loudspeaker and the rest of the amp near the preamp. Have any of you tried it ? Some people try to tell me that it is a bad idea, but when I ask if they have tried it, the answer is no. So what do you think ? Søren