I recently bought this set VT100MK1 and preamp LS15 and while I was at this seller house he demonstrated the sound from his online Tidal on TV connect optical to the DAC Luxman DA - 06 then this go to the preamp LS15 and out into the VT100. This set up sounds amazing at his house. However, when I came home play CD from the Sony X1100ES Blu-ray player RCA output into the LS15 and out to the VT100 and it sound horrible - no bass at all in any type of music. The sound sometime muffle and not clear and most importantly the bass missing tremendously. Im using a pair of KEF R900 Speakers. What is wrong here? can anyone help me correct the sounds? it is because I didn’t have the Luxman DA - 06 DAC? or it is because I don’t have those fancy hundred - thousands of dollars cable? or the CD source is playin at 41khz /16 bit not high enough signal?
This is my first system and I don’t know why I can’t get that high fidelity sound from the ARC equipments. I'm waiting for the Audioengine B1 to arrive so I can stream Spotify into the LS15. What is wrong with my set up? Thank you in advance for helping me solve this.
Just right now, i used another old 80s preamp from Sony and the sound is boomy boost of full bass and tone control was on neutral (imagine if i crank that bass up). So this confirmed the vt100 is working and my LS15 preamp is not giving that sound. Perhaps because of the faulty V3 tube? I already ordered the new tube on the way. I’m hoping replacing this faulty tube will fix my bass response problem.
@ kentrent
I assume you used RCA single ended ICs to connect the Sony preamp to the VT100. Read my post above ( page 2 ) about if the shorting jumpers were removed on the VT100. If you were using balanced ICs the jumpers must be removed.
@Kentrent, the jumpers must be present on the rear of the amp (in the two places where it says "use jumper for single-ended") if and only if the connections between preamp and amp are made with RCA cables. The jumpers must be removed if the connections between preamp and amp are made with XLR cables.
@jea48 Jim, it looks like I provided an answer to some of the questions you directed to me in one of your recent posts while you were composing that post. So as I said it seems very possible that if the jumpers are installed while the amp’s balanced inputs are being used it "could make the preamp very unhappy." And the caution you found in the manual about not using the mute function while the volume level is high would seem to add credence to that.
Regarding your question about the volume difference, the OP had said earlier that:
At the seller house setup, he only turn on 30% and i can hear music pretty loud. But when my setup i had to crank up to about 70% to hear loud.
... And I note that the seller’s speakers are spec’d as being 6 db more efficient than the OP’s speakers. I’m guesstimating that would account for about 1/3 of that 40% difference. And perhaps differences in the source components and source materials that were used, room effects, and differences in listening distance might be contributing to some extent as well. But in any event it would seem that all bets are off until the issues of the sparking tube and the shut-downs of the preamp are resolved.
My bad! The jumpers install into the XLR balanced input jacks. I must have been having a brain fart. They would have to be removed before the balanced cables could be plugged in.
All my posts about the jumpers being installed when using balanced cables are moot. It can’t happen... Jim
The jumpers install into the balanced output jacks.... They would have to be removed before the balanced cables could be plugged in.
@jea48 Jim, no, I'm pretty certain that you were right the first time. The OP said that his amp is a VT100 MkI (which I would think is the same thing as a VT100 that has no Mk designation indicated on it). Your comment that I quoted would apply to the MkIII, and perhaps to the MkII, but rear panel photos of the VT100 with no Mk designation show connectors for the jumpers that are separate from the XLR input connectors.
@jea48 Wow! Yes, it appears you were right that you were wrong :-)
And between Chip's comment earlier and my not looking closely enough at the rear panel photos I mentioned it appears that I was wrong as well. What I assumed were separate connectors for the jumpers were just printed symbols.
Guys!! Seems like my bass response problem solved. I installed an EQ and this boost the signal tremendously which now i can do tone control. This is my current set up and it now sounds amazing like it should. Fuller sound with deep bass response and clear treble with details.
CD to EQ to LS15 to VT100 out at 4ohms to R900.
(From preamp to amp using XLR and the rest are RCA interconnect)
Although i solved the bass response problem but I’m not satisfied with the sound completely since the EQ makes the sounds too artificial (even though it sounds very good). I want to be natural sounding as much as possible. Perhaps i should look into a preamp that has tone control? Or i should get a good DAC to boost the signal into the preamp? Any recommendations?
thank you again for being so helpful and wonderful. Love this community. 👍👍
If you have some standard electrical wire - i.e. the kind that runs inside the wall - you can use a piece of the ground wire, cut it down and make a jumper wire for the XLR if using SE input. If you have any music on your phone, use a 3.5mm to RCA adaptor and run it directly into the amp. At least you can isolate where the problem actually lies.
Did you check to see if the shorting pins on the XLR inputs are inserted? This was already suggested by another poster: did you check this? All your components should be performing well together. The DAC is not the reason for your problem. Are you 100% sure ALL of your components are connected correctly? How confident are you knowledge of how audio connections are made? I've ARC for decades, with now having current pieces, and have always had exceptional performance.
You were clear, everything sounded good at the sellers house. Both channels (I presume) loosing all their bass AT THE SAME TIME is unlikely if it was tubes. CHECK your connections.
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