Trumpet Troubleshoot - No Sound

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mulveling

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Trumpet Troubleshoot - No Sound
« on: 26 Oct 2013, 01:38 am »
Hi all,
Just landed a version 1 Hagerman Trumpet; was looking forward to a Friday evening listen, and of course it's not that simple. I can't get any sound out of the unit. Here's the full detail:

  • Turned on heaters; waited a minute as instructed. Indicator light stays red. All tube filaments glow as expected.
  • Turned on high-voltage; indicator changes to orange but never to green, even after a few minutes. Owner's manual (albeit for the newer version) seems to indicate the light should be green at this stage.
  • Turned polarity switches from mute to positive; there is no music coming through, nor any indication of sound-producing ability -- i.e. no ground loop hum, no tube rush, not even any switching thump when toggling the polarity switches. Indicator light always remains a steady orange.
  • Turned off unit; indicator finally turns green at this point, but slowly fades out. Only during this fade-out time, the polarity switches finally register the expected "thump" when toggled. But still no music, even at a faded/distorted level. The "thump" loudness dissipates in proportion with the indicator light.
  • I repeated this cycle a few times to verify consistent behavior
  • All other components of the system have been working consistently for months/years (I feed the Trumpet with a Bob's Devices 1131 SUT).

Any ideas? Email Jim? I have a great local tube tech / designer that can help if necessary. Was really looking forward to giving this a listen!

hagtech

Re: Trumpet Troubleshoot - No Sound
« Reply #1 on: 26 Oct 2013, 03:42 am »
Hmmm, this rings a bell - like I may have seen this behavior before.  Can't remember what it was.  Did you check tubes?  You might have to send it in.

jh

mulveling

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Re: Trumpet Troubleshoot - No Sound
« Reply #2 on: 26 Oct 2013, 03:56 am »
Hmmm, this rings a bell - like I may have seen this behavior before.  Can't remember what it was.  Did you check tubes?  You might have to send it in.

jh
Hi Jim,
I did take it on faith that the supplied tubes were OK, and assumed they were so after the heaters all lit up, etc. I'll try a completely different set of tubes from my stash before inquiring about a send-in. No rush on my end; just would love to get the Trumpet running so that it gets a fair shake in my system, since by all accounts it should sound fairly excellent.

Interestingly, one pair of the supplied tubes was a GE 6072 (i.e. 12AY7), which struck me as odd for a 12AX7 sub in a phono stage. Not sure of which slot that would be an OK sub for, so I used a pair of my Tung-Sol long plate 12AX7 instead.

hagtech

Re: Trumpet Troubleshoot - No Sound
« Reply #3 on: 27 Oct 2013, 01:32 am »
I think I know what it is - and it sounds like the machine may be working ok.  The Trumpet is extremely quiet, and with the step-up plugged in you may not hear anything.  Disconnect it so that you can hear the hiss from the 47k loading resistors.  The "orange" lamp is because I had changed vendors for LEDs at one time, and the forward voltage was a bit different, enough to cause the color error.  To compensate, R6 can be changed to 1k.  But really, operation should be ok as is. 

And I have to say, 4 / 5 "problems" with phonostages turn out to be interconnects instead.  So lets check them too. 

The 6072 will work fine, but alter the EQ a bit.  5751 are a better substitute if you don't have the 12AX7.  But give it a listen, maybe you like the way it sounds.

jh

mulveling

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Re: Trumpet Troubleshoot - No Sound
« Reply #4 on: 27 Oct 2013, 10:17 pm »
Hi Jim,
Tried a completely different set of 12AU7/12AX7 tubes (known good on last play) and interconnects; still no music. When disconnecting the SUT and listening for noise, I couldn't hear anything added to my tube preamp's noise floor (which is audible, as it's a > 20db tube pre feeding into a high sensitivity amp and 96dB speakers), besides the very faintest trace of hum. Even with the volume raised on the pre, the hum remains very very faint; it's close to inaudible above the preamp's noise floor, and may just be from the connected cables picking up hum. It certainly sounds like nothing is coming through the Trumpet; not even a trace of the input signal with the needle in the groove and pre turned up  :(

Tried wiggling the cable connectors, etc. Checked several times that nothing downstream was muted and that correct input was selected. Plugging back in the old phono stage works.

I peeked under the hood and everything seems to have good integrity; nothing scorched or loose. Any ideas, or a chance it may be something simple to fix?

poty

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Re: Trumpet Troubleshoot - No Sound
« Reply #5 on: 28 Oct 2013, 11:28 am »
If you feel you can find specific parts inside the device you can try to troubleshoot it by yourselves.
It can be something very easy like Polarity/Mute switch for example. Switch off Trumpet, unplug the mains, connect its output to an amplifier, switch the amplifier on and touch by a screwdriver or something metal the contact of the polarity switch going to the output connectors. You should hear some hum from your acoustic systems. If not - the problem is in the interconnects or just disconnected wire from the output connectors or the switch. I doubt that this is the case as soon as you should have 4 wires disconnected at once, but who knows... If you hear the hum - not plugging the Trumpet to the mains - pull out the V4 tube and do the same experiment with the pins 1 and 6. The Polarity/Mute switch at this stage should be NOT in Mute position. Depending on the position of the switch you should hear the same amount of hum from touching one of the pin. If you hear the hum, the switch works at least in one position.
Further troubleshooting should include measuring the voltage and this should be done with greatest care!!!

mulveling

  • Jr. Member
  • Posts: 8
Re: Trumpet Troubleshoot - No Sound
« Reply #6 on: 28 Oct 2013, 06:44 pm »
If you feel you can find specific parts inside the device you can try to troubleshoot it by yourselves.
It can be something very easy like Polarity/Mute switch for example. Switch off Trumpet, unplug the mains, connect its output to an amplifier, switch the amplifier on and touch by a screwdriver or something metal the contact of the polarity switch going to the output connectors. You should hear some hum from your acoustic systems. If not - the problem is in the interconnects or just disconnected wire from the output connectors or the switch. I doubt that this is the case as soon as you should have 4 wires disconnected at once, but who knows... If you hear the hum - not plugging the Trumpet to the mains - pull out the V4 tube and do the same experiment with the pins 1 and 6. The Polarity/Mute switch at this stage should be NOT in Mute position. Depending on the position of the switch you should hear the same amount of hum from touching one of the pin. If you hear the hum, the switch works at least in one position.
Further troubleshooting should include measuring the voltage and this should be done with greatest care!!!
Thanks poty. Gordon (local tube guru) should be around this week, and I'll ask him to at least look at these items. I know just enough to not electrocute myself or fry anything when poking around inside, so I'll leave it to him :)

It does seem less likely that it's a broken switch or an output connector continuity issue, since the same behavior is completely symmetric across both channels.

mulveling

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Re: Trumpet Troubleshoot - No Sound
« Reply #7 on: 13 Nov 2013, 10:35 pm »
Good news -- it was a just choke in the power supply that got jostled a bit off-kilter in shipment, and caused the connecting wires to break/fray. Gordon had initially suspected that one side of the voltage rails wasn't going up, hence the orange LED vs. green, and the lack of sound. Wires are repaired, the choke is again firmly mounted, and it's all fixed up now!

Very very nice sounding phono stage, obviously. The midrange is to die for -- natural, lush, beautiful. A very large soundstage, exceptionally powerful bass, and a grainless smoothness round out what I feel are the unit's main strengths. The overall sonic presentation is extremely musical and engaging. It seems a touch on the warm side of neutral, at least in comparison to the other stages I've had on hand (** this is with mostly stock tubes; will need to try some more combinations), and here my Rogue Ares provides an excellent alternate perspective -- faster sounding with more treble sparkle. It'll be interesting to compare the 2 over time. My system is at the best it's ever sounded with either unit.

My curiosity is certainly piqued with regards to the Trumpet reissue; sounds like the upgraded parts might make it an ideal match for my system!

mulveling

  • Jr. Member
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Re: Trumpet Troubleshoot - No Sound
« Reply #8 on: 18 Nov 2013, 05:01 am »
Rolled some nice tubes into the Trumpet: Amperex Holland long plate & Tele ribbed plate 12ax7, GE 5814 -- the stock CVC branded tubes were the Ei smooth plate 12AX7 and late-make JAN/Phillips USA 12AU7. This brought out some more detail while still retaining a touch of warmth. The excellent dynamics and powerful bass were also retained. More significantly, the soundstage expanded in every direction; this is the biggest I've heard my system! Which is a very good thing, as my Tannoy Canterbury speakers were made to sound warm and BIG. This is really a far cry from 1 of the stages I'd been using the past few months (initially planned as a temporary solution), which was a fairly nice budget(ish) tube stage that just got outclassed by the surrounding gear (I'd sold my nice VAC pre/phono to fund a Clearaudio Innovation) -- its soundstage was outright claustrophobic compared to what I'm hearing now. Then there was another stage I'd been swapping in that had a decent soundstage and nice midrange but lacked in bass/dynamics. Over time some of the fun from my listening sessions was lost, I think due to what I was (not) hearing in soundstage and dynamics. The Trumpet flat out excels at soundstage, bass/dynamics, and midrange! Over the past week, between the Ares and Trumpet, each listening session has been simply fantastic.

I'll continue to enjoy and evaluate over time -- I'm glad to have picked up this excellent stage. Already thinking about upgrading the coupling caps, but don't want to be too hasty before I've got a good handle on its stock sound. Just wish it fit nicely into my rack, as I'm sure the makeshift floor + hockey puck "stand" isn't doing it any favors  :green:

ptmconsulting

Re: Trumpet Troubleshoot - No Sound
« Reply #9 on: 18 Nov 2013, 11:34 am »
Congrats on your purchase. Yeah, the Trumpet is definitely a special phono stage, right up there with some of the big boys. Just a suggestion, I found Baldwin 12AU7's to sound really nice in the Trumpet.

Regarding the coupling caps ... If you aren't running it with balanced cables then you may want to consider doing what I did. The phase switch really didn't make any sonic difference to me, so I decided to use both sides for my own purpose. I upgraded the multicaps on one side and bypassed them with a .1uF teflon cap. On the other side I installed some nice PIO caps.

So if I am listening to some hard sounding 70's album I just flip the switch over to the PIO and things chill out and become beautiful again. It gives me some tuning options at the flip of a switch.

Enjoy,
Bob