Cavalli tube pre-amp FS or trade for your iPhone 3GS

[zzffnn]

Hi everyone,

I do not have much post count here as I can not DIY well. I do have 532 post and 52 all positive feedback at Headf:

zzffnn's profile

For sale or trade is a unity gain tube pre-amp / buffer built by dBel84 and designed by Cavalli Audio (Designer and vendor of Liquid Fire).

This offer is only open within ConUS and for:
1) experienced DIYers or
2) people who is willing to buy-it-as-it-is (note it is a prototype build).

I hate to let this little gem go but I have decided to let go all my tube gears because I do not want my 15 month old baby to touch them.

It is basically a tube pre-amp that can slightly warm up your music and broaden the soundstage. It does so without raising the output impedance (which is always less than 150 ohms), without raising the gain (gain very close to 1X) and can deliver high current to drive super long cable run without any sound degradation (don't remember the exact number but it is like 50 feet plus according to dBel84). I believe the output devices comprise MOSFET.

I will doubt check how many tubes I can include with the sale or trade. But it should at least include a $60 value “Amperex Bugle Boy” tube from Holland. Plus 2 or more other tubes.

I have used this tube buffer to warm up the sound of my Beyer DT-770 32 ohm headphones, along with AMB M3 and Gamma2 with great results. Also tried with Beta22 and LCD-2 headphones and the sound is good as well (the warmth is not needed for LCD-2s though IMHO). However, with a powerful speaker amp (DIY First Watt F2), I heard slight hiss through LCD-2s from the tube buffer (but no hiss at all when the tube buffer is paired with M3 or Beta22). I do not know if this tube buffer will produce hiss with other power amp and speakers as I do not have any at hand. I was told by an experienced DIYer that there is DC off-set during the first minute of the on/off switch, but if you tun on the tube buffer, wait for one minute, then power on the speaker or headphone, the DC off-set should not be a problem; to tun off, turn off your power amp/headamp first, then turn off the tube buffer.

This tube pre-amp / buffer is a prototype built and has slight hiss in some setting (with headphones paired with speaker amp) and DC off-set. That said, the tube buffer is working 100%. It also has a volume knob and a source selection knob that have been added to the posted photo.

For more information, such as PCB circuit design, please refer to the following pages:
Found: Cavalli tube buffer
DIT tube buffer?
HeadWize: DIY Workshop > Tube Buffer for Line Level Operation

I will either sell it for $150 shipped or trade it for an iPhone 3GS , with paypal cash from my side . I apologize that I can not offer much more technical information. If you are a DIYer, you probably will be able to gather more info and understand it better than I did/do.

I may be able to ship to Canada if you make up the ship cost (check with USPS for shipping cost). But I can not ship to anywhere else except for ConUS and Canada. Sorry I am not consider any other trades.



I bought this tube buffer for $150. And I was told by several experienced DIYers that the part cost inside of this little gem is easily $100. I think the tube buffer has Alps27 (or RK27? not sure exactly which, but it is a decent volume pot), a decent transformer, MOSFET, home-made PCB and a ground loop breaker. It also has a volume control, a on/off power switch, a input selector to select between 4 RCA inputs, a RCA output and one 3-prong power socket. It takes one 6922/6DJ8 tube.

You may also contact me at zzffnn at hotmail dot com for fast response.

[zzffnn]

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