Getting some glass for my ****.

ben62670

I'll put it with the rest;)

Systems

disneyjoe7 wrote: »

Wait for the Bill

Universal healthcare, embrace it.;):eek:


Like those Wima's .I used the MKP 4's in one of my BOZ pre's.

ben62670

A lot of people talk crap about universal Health Care but Canada has it going on. In the USA you are EFed without insurance.

Systems

Our system has it's problem but many advantages.

ben62670

Well it has been running for about 16hrs. At first it sounded good, but then at lower volumes it sounds distorted. Again only 16rs, but I am in a hurry here! BTW the distortion is in both channels, and for now the pot is after the pre, and the pre is being used like a buffer between the Denon 2900, and my passive 100k pre. Don't know if that is an issue. The gain is 16db.

disneyjoe7

Too high of a gain for a buffer? Just thinking at loud.

ben62670

The funny thing is when I turn up the volume(again the pot is after the tube pre) it cleans up.

disneyjoe7

Since pre amps and I assume buffers are designed to work in class A mode, is the bias set too low? Where the higher volume you have a cleaner sound due to a better signal to noise ratio?

ben62670

No idea. I need to not over analyze it till I get some time on it;) I must say the 2900 is playing real sweet SS since the mods. I have two outs on the Denon so I just switch between "the two sources" for an AB kinda thing.

disneyjoe7

Need a tone generator and a scope.

disneyjoe7

Or turn up to cherry plate level note bias, then back down to 40% of that level. Should get you close, may waste a tube in the process but it's all in a TEST

ben62670

It's regulated to 12.16vdc on the heaters. Not adjustable. I did change places on two of the three tubes. Sounds better. It may have been a bad connection which makes sense. The higher signal voltage could cross the resistance of the bad connection better. IDK the tube thing is new to me.

disneyjoe7

Bias to a tube isn't the heater Bias is the grid voltage which controls plate current?


Still thinking, what do I really know?

ben62670

fixed

disneyjoe7

How?

ben62670

Don't use both sets of outs for L+R on the Denon at the same time;)

george daniel

ain't no solid state behind this man,,tubes,,you'll have to guess who he is,, should not be too difficult,,sorry for threadcrapping,,temporary loss of self control.:)

Edit-- taken in Chicago while playing "Dazed and confused"
DUMBA$$ edit--can't remove the name from the pic--oh well.

ben62670

I am in need of more tunes:)

Systems

I take it you found 2 more zeners?

ben62670

That pre is still not done. The other pre had the zeners. They looked like regular rectifying diodes. All the zeners I have seen looked like little glass beads. The distortion is back again at low volumes:(

Systems

Yeah some zeners (I believe the 1 watt'rs) look very similar to the 1N400*series rectifier diodes.

ben62670

http://www.youtube.com/watch?v=zjrSAuhTFPE

The internet is a wonderful tool:)

ben62670

Well I have tube project number 3 done. I was missing 2 zeners. I used an LM7824 instead. I will correct it when PE sends out my parts.

disneyjoe7

Ben,

I confused didn't have a kit amp? Why are you trying to re-engineering the amp with other parts?

I'm afraid to ask what are you trying to do?

ben62670

This is the kit tube buffer. This is the one missing the zener diodes. I installed a voltage regulator in it for now. Later when my parts come in I will replace the regulator with the correct diodes. I have a new found love for zeners in the PS. They are nice and quiet. The regulator has some noise. The kit was only $60. I am going to replace the tube. I think this buffer sounds very close in SQ to the Grounded Grid pre. The modded Denon 2900 performs great, but the symbol spash isn't as good SS, and the mids are a little sweeter. Not a big difference, but a difference non the less.

hearingimpared

ben62670 wrote: »

No idea. I need to not over analyze it till I get some time on it;) I must say the 2900 is playing real sweet SS since the mods. I have two outs on the Denon so I just switch between "the two sources" for an AB kinda thing.

I definitely want you to mod mine.

ben62670

hearingimpared wrote: »

I definitely want you to mod mine.

Consider it done my brother. It makes me shake my head in disbelief how simple it is. I just don't get why they don't do it from the factory that way

ben62670

Well I have the tube buffer running. The little one tubed wonder is pretty damn sweet with less than 3 hours on it.If it improves like the GG pre I will be stoked. I got the goose bump now:)

ben62670

Well I have a Raytheon/CBS tube on the way for my tube buffer. I described what I don't like about the upper mids and he decribed what it was to a T.
He name is Brent Jesse, and he is a pleasure to deal with:)
http://www.audiotubes.com
Ben

NJPOLKER

Did he go over his return policy with you? Your right he is awesome to do business with.