My shanlingplayer is the first 10 seconds not DC free so i must wait 10 sec before i press play the first time. Still some residual hum. Post 4 of 6. Remove the 3,3uf Obbligato across the tube and OPT. Jan 14, at 7: The red ohms resistor was not present in the TRAM circuit.

Uploader: Jushura
Date Added: 22 January 2006
File Size: 21.2 Mb
Operating Systems: Windows NT/2000/XP/2003/2003/7/8/10 MacOS 10/X
Downloads: 38314
Price: Free* [*Free Regsitration Required]

Keep the 1K Gridstopper as close to the actual gridpin of the When I had this suggestion from “Peter”, I thought he’d made a typo or something. Building the 2, June Does the in reality 66n6p a serious problem with microphony?

6n6p operating point?

The outcome of all above is two versions of the line stage. Now, a rotary switch used for an attenuator has to be shorting and turning this one up for the first time made the poor test drivers’ cone pop out of the magnet gap and the voice coil stayed on the pole-piece Moving wires around at any stage during construction didn’t make any reduction in hum at all.

Description Postage and payments. I never do high-gloss painting as I do not have the facilities to do so.

DIY tube preamp SRPP ECC88 E88CC 6N2P 6N6P | eBay

This will have a potted 50 mH choke to make an overall nice appearance. Post 5 of 6. This reduced hum considerably and one channel was silent.


May not post to United States – Read item description or sfpp seller for postage options. The philosophy behind this approach can be read from Lynn Olson’s lecture on current loops: Changing filament supply to DC helped somewhat, but the main problem is likely to be the mains transformer being too close to everything. I’m not sure about the rationale behind this capacitor, but removing it is an obvious option.

Does it improve the sound? Right now my w. When I make a change and treble level seems to has gone down – sr;p it really hasn’t – then things are moving in the right direction. Use a higher value resistor, for example 1K2 or no resistor at all but then you have to test the frequency response and see if it is still OK I will look now and then to your progress! Kiwame resistors and Obbligato film caps used in most places.

I read a lot of the modifications with were possible but nowhere a read about using a tubebufferstage for the Ucd. Question 66n6p what operating point shall i run at?

Universal PCB for tube pre SRPP/CCDA ECC88 ECC82 from stereo24 on Tindie

Morgan jones does warn of oscilliation, but i could try and scope it. For the heather voltage you can use 12 V by putting two tube heaters in serie. Sibilance is significantly reduced compared to and high piano notes appear to die faster.


Finally, the line stage, version 2 is playing and measuring the noise level on the CLIO looks satisfying.

Here the combined schematics. The line stage has now been playing for a month and a half – I needed a brake – and a few holidays have been spent finishing the construction, that is: No change in hum.

This is probably the most neutral sounding valve I have tried yet and it made me go trough my music collection again, picking out flutes, piano, violins, etc. Have tried increasing cathode resistor. 6np two versions of the line stage.

OT load is increased to 1. Only half is used and heated per channel.

You must log in or sign up to reply here.