Tube headphone amp as pre amp to solid state? - Page 2

Quote:

Originally Posted by mordy 

Hi Uncle Erik,

 

Thanks for your post. I have used the Little Dot MkIII in an external loop to my receiver for over a year, and I have not come across any distortion unless I turned up the Little Dot full tilt, which I attribute to clipping in the LD amp. The LD has preamp out RCA connectors.

My receiver has U shaped jumpers between preamp out and main in, but it seems that I cannot switch off the preamp; however, I could apparently add another amp instead, bypassing the built in amp.

I spent a lot of time tube rolling and I have found combinations of driver/power tubes that I am very happy with. I have never heard of Bottlekit before, and I am not sure if you have to build them yourself or if they are ready made. I'm not ready to build anything myself, though.

Curious to know what you mean with reliability of Little Dot. The only problem I have had is a Russian power tube go bad on me. I haven't really seen any reports of people having trouble with them.

What kind of preamp do you have that has such flexibility?

I'm not sure how you have it hooked up, but you shouldn't run a preamp to a preamp to an amp.  You might want to simplify things with an inexpensive Adcom GFA-535 amp.  They go under $200 and are a good design.

Yes, Bottlehead sells kits.  They're an easy build, fully documented and they have a forum, too.

I've seen several Little Dot threads here dealing with faulty amps.  The big problem is that they're not worth fixing - it's cheaper to buy a new one if there's a major failure.  I plan to keep my gear for decades and all of it has to be repairable.

My preamp is a Conrad-Johnson PV-2.  Found it on Audiogon for about $300.  It's been great, though I've outgrown it.  An upcoming project is an Electra-Print Ultrapath preamp.  I'll give it a dozen source inputs, the ability to switch between six headphone amps, and at least two power amps.  It'll be the heart of the rig.

Hi N,

Looked up the specs for your NAD amp. This is what it says: "6 Line Level Inputs including 1 Tape Loop."

Regarding my Outlaw RR2150 receiver I called the factory support and asked if there is a drawback running two preamps - solid state and tube into the amp.

I was told that it should not be a problem at all. What we are worried about is distortion, and my receiver has very low distortion, and normally I cannot hear any hum at all. The external loop I have does not introduce much of extra electronics and should be very quiet, as evidenced by me using it extensively.

I asked about inserting the tube preamp into the tape loop. Here the tech told me that this is further downstream of the signal and involves more electronics and processing, and that the sound would probably be better using the external loop. Since you do not have the external loop built in, I would suggest to try inserting the Little Dot into the tape loop and see how it sounds. For headphone listening the Little Dot is superb, and if you are lucky using it in the tape loop might work very well.

I read the manual for the NAD 315BEE  and nowhere it states a tape monitor loop is available. The tape output mirrors what is selected for input source and the tape input is for playback when the tape input is selected. One way to be sure is to select the CD input and press the tape button and if both light up you have a monitor loop capability.

Dear John57,

I googled the amp and this page come up (not the manual) - see what you think about the tape loop. (4th line with bullets)

http://nadelectronics.com/products/hifi-amplifiers/C-315BEE-Stereo-Integrated-Amplifier

Mordy,

I saw the specs saying a tape loop but I stated earlier it does not seems to be a real tape  monitor loop according to the manual. It seems that the specs is saying that what input is selected is looped to the tape output but you can not have the selected input going to tape output and back to the tape input to the amp section at the same time. Originally the tape monitor loop is used for cassette desk that has at least three heads that you can use to monitor the recording right after the recording head. I ussually read both the specs and the manual to see if what the specs is saying is what I think it is saying. He still can use the NAD as a input selector and connect the tube amp to it and use the tube amp pre-amp output to an active speakers for example. The Panasonic SA-HE200 6.1 is a example of a receiver that has a tape monitor loop fuction.   is a example of a 6

It shouldn't be a problem. Your tube amp is like a source to your integrated amp, as long as you don't overload your integrated amp's input. They usually can take up to 2v input.

Nicholars,

Agree completely with wuwhere. The only question I have is how much you have to turn up the volume control on your NAD315 to get sound loud enough for listening to your speakers. If you have to turn up the volume control all the way it may introduce distortion. If you can do with a lower setting on the volume control for satisfying playback levels everything should work out fine.