1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.

    Dismiss Notice

Inspire IHA-1 tube headphone amp

Discussion in 'Headphone Amps (full-size)' started by burn1, Oct 18, 2014.
10 11 12 13 14 15 16 17 18 19
21 22
    A18, K10, vega... actually my main phones is LCD4 and potentially also Utopia, but sometimes I want to listen iems and I read it woulkd be bad...
    so is it possible to listen A18 on this amp or it would be noisy?
    Last edited: Nov 21, 2017
  3. Jacobal
    Has anyone tried the 274b Taks or WE or something similar upgrade tubes with this? I might get a KA 274, which is said to be just as good as Taks for a lot less cash.
  4. attmci
    Man, You had paid way too much for those tubes. There is no bad boy tube called 6SN7GTA. The mullard GZ34 is a reissue. I won't pay more than $10 for a GE 6BX7.
  5. Jacobal
    If those tubes sounded good, imagine how much better a WE 274b would be.
  6. Aornic
    I'm curious about the WE 274B but I'm very happy with my metal base GZ34 + 6F8G pairing in the meantime.
  7. Jacobal
    Does the balanced out make any difference?
  8. DelsFan
    Let's let someone who owns this amp reply definitively. Whereas I just hope to order one soon.

    I remember reading that the four-pin balanced output is offered for convenience, for people who already invested in a high quality four-pin balanced "style" headphone cable. Supposedly the signal to that output is exactly the same as the signal to the 1/4" jack (coming from the same place, or jumped directly off the wires going to the 1/4" jack?). Maybe someone will weigh in on whether or not one output or the other sounds any better - I expect the designer intended for them to be similar or equivalent or exactly the same.
    Last edited: Nov 30, 2017
  9. Aornic
    This amp isn't balanced. Both outputs sound exactly alike. Furthermore, if you plug in two headphones at once it doesn't degrade the signal from when only one is inserted either.
  10. Jacobal
    So basically, balanced output would only benefit if there was a balanced input.
  11. DelsFan
    My young Electrical Engineering student nephew and I were discussing this over Thanksgiving; he has a Pro audio background only and has been involved with large room and theater sound and lighting since he was 14. I "only" have a Civil Engineering degree, and have been involved with two-channel audio since the late 1970s.

    Preface, I'm going to tell you "more than I know", and I'd be happy for others to correct my misconceptions.

    1) It seems that when a tube amp is described as balanced it is not usually referring to the same way a balanced solid state amp is... balanced. Maybe the balanced solid state amp includes a balancing transformer (summing in phase and out of phase signals) whereas the tube amp just makes use of the isolated ground. Maybe.
    2) In Pro audio, balanced connections are ideal because the design allows for cancellation of the interference accumulated over long cable runs. For concerts, a 100' run to a sound board would be a short run.
    3) In a Pro mixing board, the first thing that happens to the balanced signal is the in-phase and out-of phase signals are electronically processed, the volume (gain, I know volume is the wrong word) is sometimes doubled as the out-of-phase signal is processed and added to the in-phase signal - and the in- and out-of-phase interference is summed so it mostly cancels itself out.
    4) In the Dragon Inspire this does not happen; but the signal is also not degraded since the amp doesn't have the added electronics (balancing transformer?) necessary to process the in- and out-of-phase signals into one in-phase signal.
    5) A three-pin balanced cable has a ground, plus two pins carrying the audio signal - one in phase and one out of phase.
    6) I think a balanced amplifier design has more to do with keeping the right and left audio signals separate, and probably isolating the grounds,and does not have anything to do with summing in- and out-of-phase signals in order to reduce background noise.
    7) I'm surmising the 3-pin balanced inputs on the Dragon Inspire simply ignore the out-of-phase signal being sent, and is offered for the convenience of people who already own high-end balanced interconnects. The signal is processed the same inside the amplifier whether the connection is single ended RCA or three-pin balanced (with the balanced inputs, the signal from only two of the pins are "recognized" by the amp). There might be some benefit derived from the ground having been isolated at the DAC. It's a theory.
    8) The same with the four-pin balanced headphone output; the balanced out derives its signal from the single-ended RCA output (internal wiring) so there is a ground and an analogue signal for the left and right channels.


    OK, the previous points can serve as an example of how to take a set of facts partially understood and put them in declarative form. Except I claimed at the outset I didn't know all I was saying.
    I went to look up a term and stumbled on this site, WRITTEN BY PEOPLE WHO ACTUALLY SEEM TO KNOW WHAT THEY ARE TALKING ABOUT. Here is the link; I think this site explains the difference between balanced cabling and "fully" balanced headphone design.


    One excerpt:

    "The most common use of balanced audio signal transmission has actually little to do with driving headphones in balanced mode.
    In many professional audio applications, signals are routed from place to place via balanced cables in an effort to reduce common mode interference from radio frequency (RF) noise sources like fluorescent lights and motors.
    Because the voltage developed on the transmission line from RF interference is identical on both normal and inverted signal conductors, and because the balancing transformers [my emphasis] only allow current flow when the signals are opposing, the common interference signal is cancelled out.
    This problem is not typically an issue even with single-ended headphones because the low output impedance of the power amp prevents a significant RF interference noise voltage from ever developing. But there are other excellent reasons to drive headphones with a particular type of balanced amplifier.
    Certainly, there are a number of amplifier designs that are single-ended internally, but use transformer coupled outputs; these amplifiers improve headphone performance largely because of the removal of the common ground."

    Now I have to get some winter wheels for my sister's newish car - but I hope the link was helpful.
    It does seem actual owners of the Dragon Inspire concur: there is no difference in sound between the 1/4" headphone jack and the 4-pin balanced output since they are both operating in single-ended mode. (And, both sound spectacular.)
    Last edited: Dec 2, 2017
  12. djd1122
    @comzee, How do the Shuguang WE6SN7 and Shuguang natural sound series CV181-T (6SN7) sound compared to the Tung-Sol 6SN7GT black glass round plate (BGRP)?

    Last edited: Dec 25, 2017
  13. comzee
    Let's start between the psvane/Shuguang, and also add one.

    #1 Psvane Treasure Mark II 6SN7 (This is the one that is grey bottle)
    #2 Shuguang WE6SN7 (this is a replica model, clear bottle, funny enough tho Western Electric never made a 6SN7, so hmm)
    #3 Shuguang natural sound series CV181-T (this is black bottle)

    Out of those 3, I personally like #1 the best. It's brighter than both of the others, but easily has the best resolution (detail retrieval) and has more air and clarity.
    #2 you can basically just throw #2 out as an option, it's low resolution, and fuzzzy, (like not clear).
    #3 is extremely warm. If #1 is one notch bright, #3 is 3 notches warm. It's just slightly less resolution and air than #1, but still easily bests #2, it's not fuzzy like that one.

    So now the BGRP, this is clearly the best out of all of them. Extreme resolution, extreme clarity, extreme air, but it's 1.5 notches bright (in the context of the previous impressions).
    If you can get a rectifier to warm them up a bit, they're suburb, or if you already like a bright leaning sound.

    My favorite tubes for IHA1 by far are the 6F8G version of the BGRP (well 6F8G is actually it's predecessor).
    You'll need converters for them, but they have the same resolution and air as BGRP, but a more even and neutral FR.

    To be specific too, there are many version of 6F8G just like there are 6SN7. The specific 6F8G I'm talking about also has black round plates, and black carbon coating, with distinct silver flashing on the bottom.
    Here's a visual (not my picture) of what they look like

    Also you didn't ask, but my two favorite rectifiers are Metal Base GZ34, and 596 (596 needs converter).
    Metal Base GZ34 is very even tone, 596 is just a hair bright, but both produce exceptional resolution.

    P.S. If anybody has read one of my previous posts where I suggest 6C8G tubes, I'm ashamed of that post, those suck for iha1, avoid them.
    Last edited: Dec 25, 2017
    djd1122 likes this.
  14. Jacobal
    I’m selling the IHA-1 if anyone’s interested.
  15. Stevtt Contributor
    Does anyone have any idea how this would rive HE-500’s without the transformer upgrade?
10 11 12 13 14 15 16 17 18 19
21 22

Share This Page