Am I crazy - tube pre-amp with receiver??

Hi - I am a newbie (but avid reader of this forum). I have a newbie-like question which arose from some extrapolating I am doing.

I hear you can use the TAD-150 pre-amp with the TA-30 Integrated amp, by using the TA-150 as input to the TA-30, and just leaving the volume knob of the T-30 turned up. I hear that this is supposed to provide some sort of benefit over using the TA-30 alone. What one gets outside of remote control is not clear to me - but I digress . .

I have an old Harman/Kardon 3400 reciver, who's remote control no longer works.

Now - what would happen if I plugged something like the TAD-150 pre-amp into the H/K, and used by H/K as an amp (just keep the volume turned up)? The desired result is to improve performance, incrementally work towards a better system, and regain my remote control.

Would this work? Would I see any benefit?

This weekend, I was told by a stereo salesperson that one could get the majority of tube amplification benefits by going with a tube pre-amp / SS amplifier. So I am putting 2 and 2 together here, possibly to only get 1. Ha.

Regardless, the whole point is to incrementally upgrade - and this is one way I came up with. Thoughts? Is this stupid / insane / waste of time & money?
Hi Matthew, I don't think this approach will sound better. You would basically be using two pre-amps, the external one and the one built in in your receiver. An input on a pre-amp is designed to take a certain kind of input, let's say 500 mV. It will amplify this to a higher level which is enough to drive a poweramp. What you are doing is amplifying a signal so it's enough to feed a poweramp, and then amplify it again. Not only useless, but you might be overloading the input on the second preamp, which will cause distortion.
However - some integrated amps, or even receivers, have preamp-outputs and poweramp-inputs. This means you can use another preamp feeding the poweramp, or vice versa. I don't know the H/K, so I don't know whether it can be used that way. That might improve the sound a bit, provided the preamp you're using is of better quality then the one built in the H/K.
As for a combination of tubes and ss - I'm using that, a simple tube preamp and a monster Class A poweramp, and I love the sound. But that's no guarantee for succes, I'm sure there are plenty of combinations of tubes and ss that will sound awful. So - listen, and trust your ears.
If the HK receiver has pre-outs AND power-ins and these two can be disconnected, you could use a tube pre-amp and connect the R&L outputs of the pre-amp to the R&L power-ins of the receiver. This would be the desired setup you seek, but I don't know if the HK has power-ins. Also, I don't know if the incremental benefit would be cost effective.

If your system is 2-channel only, I would suggest waiting until you can afford a quality integrated amp and replacing the receiver altogether. If you want to continue to use the tuner from the HK, just connect the pre-outs or tape out to the new integrated amp.

BTW, I have owned the Cayin TA-30 in both stock and fully BizzyBee mod'd styles. It is very good for the price!


I recently built a new line-stage from a kit. To test it, I connected it into my system ahead of my Cary SLI-80 integrated amp. Surprize; this sounded way better than the Cary alone. BTW - this is one sweet preamp: tranformer coupled with Lundahl trannies, differencial parallel-feed gain stage, etc. The sound was more lucid, more of that PRAT thing. The leading edge of the notes better defined. And QUIET. I'm running the vol. control on the Cary at ~10-11 o'clock. This might not be the case every time, but in this instance running a preamp ahead of an integrated was a sonic improvement and not a small one either. The Cary is now a "power amp".
Thanks guys - this is all helpful.

I am away on business - so I can't look behind my H/K - but I HIGHLY doubt that there is a pre-amp input. My guess was that the pre-amp would "overwhelm" the receiver if plugged into one of the component inputs.

I did not realize some / many integrated amps had pre-amp inputs. Now this is all making sense. Still, in looking at the Cayin TA-30 specs/photos, I don't see a pre-amp input - so I don't quite get how people are using the TAD-150 with the TA-30.

John - cool to hear about your home-built pre-amp. So - does the Cary have a pre-amp in, or are you using one of the component inputs?
hey matthew,i wouldnt leap to the conclusion that your hk dont have a preamp in,i vaugly remember that model reciever & i do believe it has it.

what your lookin for will not be a regular looking input but 2 side by side inputs that are coupled from the factory with "jumpers" that look kinda like big ass staples.

if you have these jumpers you simply unplug the jumpers which will disconnect your preamp section from the power amp section & plug your new preamp into the power amp section in place of the jumpers & your in like flynn.

i gotta believe the tad will be a huge improvement from the built in stock pre section in the hk reciever.

dont be afraid to try some creepy stuff with what you allready have as john tracy pointed out in the above post sometimes the goofiest stuff ends up being the best sounding.

The Cayin (TAD) does not have amp inputs. When used with an external pre-amp, you simply connect the pre-amp L&R outputs to one of the inputs on the Cayin (like the aux. input). The "pre-amp" section of the Cayin is actually passive and only has the volume control pot in the circuit. You would simply turn the volume control to max. and theoretically this will pass the signal through to the amp intact.


That's what's "crazy". I'm using one of the component inputs on the Cary. Setting the volume control on the Cary to ~10-11 o'clock puts the volume control on the line stage @12-3 o'clock. Right now the line stage is driving my new 2A3 SET amp that is "burning in".
Finally - home sweet home.

Bigjoe - checked the back of the h/k - no dice - no pre-amp bypass. Thanks for the suggestion.

John_tracy - thanks for the encouragement. I suppose I will go with speakers first. I guess I'll keep thinking of how to update the amp / pre-amp. I may yet try to use a pre-amp into my receiver, if I find a good deal here.

If you need remote for volume control, try this Jolida passive pre (make sure to use very short interconnects):

It's only $240.

Creek makes a remote volume control to for a bit more (but shaped more like 1/2 the length of a small shoebox).

I'm considering the Jolida for a similar amp I just got this week, the PrimaLuna (the Cayin was out of stock).

Just a few minutes ago I had my reciever's tape out hooked up to the Prima so that I could at least control my tuner stations, source selections , and CD controls. But I got some low volume hum caused by the long CD cable connecting to the receiver. Got rid of the cable and the hum at the same time.
What is the difference between a "passive-pre" and an "active-pre"?

Also - what is the definition of a "line stage" amp?

"passive pre": a volume control only (aka "attenuator"), offers no gain. The device can also allow switching b/ween diferent sources. As such, "passive" preamplifier is a misnomer/ contradiction: passive devices do not amplify
"Line stage": (pre) amplification of all sources (cd, tuner, etc) EXCEPT phono. The phono requires a special filter.

Two more questions (one objective, and probably subjective):

1) If passive-pre's "work" - why have an active pre? What is it doing?

2) Is it true that one can get the majority of the tube benefit by employing a tube pre-amp with a solid state amp?

1) Mostly a matter of electrical (impedance) matching of devices -- and personal preference, I guess. I only use active preamplification for my phono. None for the rest.
2) Mostly, yes. Tubes are excellent for amplifying low level signals.