Volume Problem Trouble Shooting Ideas?

I have been trying to figure out the source of a problem and getting nowhere, so I was hoping to get some input from Members here that are FAR MORE advanced than myself. I will outline my setup and then detail the listening problem. The Amp is a Dennis Had Inspire 45 tube amp with brand new Emission Lab tubes, the Preamp is a Dennis Had LP3.1 with NOS tubes, Turntable is a Dual CS-5000 with an Ortofon cartridge and Sutherland KC Vibe Phono Preamp, Streaming is with a BlueSound Node, CD Transport is a Cambridge Audio CXC V2 with a Cambridge Audio DacMagic 100, Speakers are Polk Audio Monitor 10B, Interconnects are Monster Cables I’ve had for years, and the speaker cable (THIS IS WHAT I AM REALLY INTERESTED IN) is DIY from Amazon Basics 16 Gauge 1.33 mm with Amazon Basics Spade Terminals. The speaker wire is approximately a 16’ to 18’ run.


My listening problem: When I start listening to music FROM ANY SOURCE, either immediately or in roughly 10 minutes, all of a sudden the Right Channel Speaker volume drops significantly...to about half of the Left Channel Speaker volume. Then after a while, the volume equals out again. As I continue listening, sometimes the volume in both speakers will then suddenly reduce by approximately 25% to 30% -- then after a short period increase to the original louder level. Sometimes the volume stays the same level in both speakers for the rest of the listening session, other times the Right Channel Speaker will decrease again.


Before hooking the Amp and Preamp up in this current listening area, they worked perfectly and did not have this issue. When I flip the speaker cables the issue flips to the Left Channel Speaker. The tubes checked out as OK when the issue first started, and the Emission Power tubes in the Amp are brand new out of the box. I had this happen with another Tube Amp I own, and the first item in my troubleshoot checklist was the problem...a bad Power Output Tube. Bought new Power Output Tubes from Brent Jesse and problem solved. So that was the first thing I checked but the Tubes checked as OK -- plus the Amp Power Tubes were brand new out of the box $800 Emission Lab 45 tubes which are known for their quality.


Sorry for the long lead in, but I have seen from other posts over the years that Members like to have a lot of information about the gear and troubleshooting already done. So I’m finally getting to my question: CAN THIS VOLUME DROPPING AND SUDDEN INCREASES AND DECREASES BE CAUSED BY THE SPEAKER CABLE? IS AN 18’ RUN TOO LONG OF A RUN FOR 16 GAUGE CABLE? I know the first thing most of you have thought, "Dummy, why don’t you just connect another pair of speaker cables from your Amp to the speakers and see if that fixes it!" A few reasons: Currently, the speaker cable is heavily fished throughout a custom designed built-in bookcase/cabinet and is rather difficult to access. I’m partially disabled from back issues and degenerative joint disease, so I can’t easily reach the back of the Amp to run new speaker cable to test that theory. In addition, I don’t have 12 or 14 gauge cable that is the length needed, and don’t want to buy the new cable if that can’t be a possible reason for the problem. Without completely breaking the gear down, I’d need about a 10’ run of newer gauge cable just to connect to the back of the amp and stretch the speaker cable across the cabinet to reach the speakers to test the Gauge theory.


If you tell me that yes, indeed, the speaker cable could be the source of my problem, I don’t mind buying a 100’ spool of 12 or 14 Gauge cable off of Amazon and creating another long run set of Speaker Cable. I already have a box of 8 Gold Plated Banana Plug terminals, so I can build another set of Speaker Cables. If you tell me that, no, speaker cable can’t cause this issue, that leads me back to having to try and test the tubes and hope that is the issue and not that something is going on internally with either the Amp or Preamp. If I do have to reexamine the tube theory: I know on the Amp the power tubes are the new Emission Lab 45’s. I have the original power tubes that I replaced, so switching that out to test isn’t an issue. However, can you tell me which tubes on the Preamp might be the culprit? I do not know the tube arrangement on a Preamp -- such as does it have power tubes and rectifier tubes like an Amp? I’ve only owned the Dennis Had gear since last May, and as with most Dennis Had gear, there is not a lot of paperwork or manuals. He has responded to a couple of emails I’ve sent, and he has invited me to come to his garage to look at a Phono Preamp he is building (Dennis lives in Cary, NC, and I live in Winston-Salem, NC, which is only 80 minutes away). I thought I might get quicker answers on this site.  


EDIT (I FOUND THIS INFO IN A SOLD PREAMP AD):  This preamp is the best preamp I've ever had--bar none. Will ship with the original Sylvania 6sn7 tubes Dennis included which, incidentally, are the best 6sn7's I tried, beating out many higher end tubes; additionally, I will include another 6sn7 in the place normally reserved for a single 6bx7. After the 6bx7 died, Dennis recommended I replace it with the 6sn7 and I preferred it to the 6bx7. It will ship with the original EH 5u4 rectifier, which I found to be a great rectifier, plus two 6dn7 tubes, which sound fantastic in place of the 6sn7.


Thank you greatly in advance for any help. It is very frustrating to finally get this extra listening room set up in my Den with a "nice to me" Amp and Preamp, but not be able to appreciate my listening sessions!


IMO, the speaker cables are unlikely to be the culprit.

In order to diagnose the problem, my suggestion is to bypass the preamp and use a BlueSound Node to connect directly to the power amplifier. Use the BlueSound Node to control the volume. If the problem persists, it is likely that the power amp needs repair. If the problem goes away, the next thing to do is to put the preamp back into the system to see if the preamp is the cause of the problem.

If you can't do it yourself, find someone to help you.


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I'm not 100% sure on the amp but if its a 45 tube based amp you could be having issues with too little power. 1.5wpc-2wpc is not enough for your speakers and you could be over driving the tubes/transformers/etc. Personally I would not run a SET 45 Tube based amp on any speaker below 98db.


The polk's are: 

Type: 4 driver loudspeaker system

Frequency Response: 25Hz to 26kHz

Recommended Amplifier: 20 to 250W

Impedance: 6Ω

Sensitivity: 89dB


@glennewdick -- Thank you!  I feel like an idiot now 😆.   After reading your post, I quickly researched and found, indeed, the Dennis Had 45 is rated at 2 watts, with many users thinking it's 1.5 watts.  EVERY owner said the same thing -- you must have high efficiency speakers, and when you do it is a magical amp and preamp.


I had read the wrong info on my Polk's and thought they were in the low 90's in efficiency.   And am sitting on a pair of Klipsch Forte II's that I was going to use in another setup.  A large amount of Had owners use Klipsch.  I really feel like an idiot.


I have a McIntosh MC-225 and ARC SP-17 -- would that amp handle the Polk Monitor 10's?  I just have nostalgia for the Polks, and want to use them.  I'm going to have to totally rearrange the systems in my house -- the Forte's won't fit where the Polk's are, and I'm now certain I've been over driving the amp pushing the Polks.  Thanks for your keen eye.

The 45 tubes are IMO the best sounding SET tube but also one of the lowest power avail. They would be quite good with your Klipsch's. I'd recommend you visit Crites speakers for some updates on the forte's, tweeter and crossovers would be my recommendation. 

the MC-225 would work with your polks if your listening at lower levels but its still only 25wpc so your not going to get to concert levels but will probably work nicely if your reasonable with the volume.  

If you have a digital multi-meter check the resistance from end to end of the cable. It should read at the lowest end of the scale around 0.1 ohms. Anything more and the cable is eating up the signal. The resistance will read more if the connectors are not on tight.

Amazon's OFC copper wire speaker cables are excellent, however their connectors suck. If you use good quality 1/4 closed seam spades crimped tight or connectors with two set screws you will get a good connection and a very low resistance. This might solve your problem.

@glennewdick 👍👍

I mistakenly thought the OP was running the same setup using the same speakers and had no issues until now.😆

Before hooking the Amp and Preamp up in this current listening area, they worked perfectly and did not have this issue.

I prefer the 845 tubes but the 45 tubes are great sounding also.  If you need assistance, I am located in New Jersey.

I'm sorry.  Explain to me the justification for buying a 1.5 watt amplifier.  Headphone amps have more power than that.

@imhififan -- I should have been more clear with my statement, "Before hooking the Amp and Preamp up in this current listening area, they worked perfectly and did not have this issue."


What I meant by that statement was when I auditioned the Amp and Preamp at the previous owner's house.  The previous owner is a friend of mine that I met through my local HiFi dealer, and I listened to the Dennis Had gear at his house several times before convincing him to sell them to me.  He had the gear hooked up to a pair of Klipsch Heresy's, and the volume issue never happened at any time I was at his house.  Sorry for the confusion.  

@bigkidz -- Thank you for the input.  I'm in Central North Carolina, but if I'm ever up your way I will certainly give a holler!  I'm not familiar with the difference between 845 tubes and 45 tubes...I will research that online.  I do know that the Emission Lab 45 tubes that I rolled in place of the original tubes Dennis included are AMAZING and I can hear a big difference when the volume is not acting crazy.  My friend included the brand new, still in the unopened box, Emission Lab tubes for free when I bought the amp and preamp.  He had made a $1,500 error in pricing in a previous deal we made, and when he discovered it, I made him whole instead of making him eat the loss.  It kept his wife from going ballistic, so he said he owed me a BIG FAVOR.



the MC-225 would work with your polks if your listening at lower levels but its still only 25wpc so your not going to get to concert levels but will probably work nicely if your reasonable with the volume.

It will be in one of my listening rooms that I don’t play music at loud volumes, so hopefully it will be fine. The only way to find out is to hook it up and see. In a worst case situation, I can move the Polk’s to a room that has a solid state Pass Amp and I KNOW the watts per channel won’t be an issue! I know that a majority of the Members here wouldn’t give the Polk Audio Monitor 10’s the time of day, but they hold a sentimental value to me as they were the speakers in the first system my wife and I bought a year after we were married, paired with Nakamichi components. I still have all the Nak gear, so I might hook it all back up together -- I love that Nelson Pass designed Nak SR-2A Stasis Integrated Amp.


Also, my Forte's have had the Crite's Crossover upgrade.  Thank you for mentioning that.

@jhnnrrs --

I'm sorry.  Explain to me the justification for buying a 1.5 watt amplifier.  Headphone amps have more power than that.


I don’t know, explain buying an amp with 500 watts per channel. Believe me or don’t believe me, but the Dennis Had Inspire 45 with 2 watts makes my Klipsch Forte’s sound incredible, and I’m not even coming close to using all 2 watts. Why do you need all those watts per channel if even the first watt sounds like crap?

I'll bet it sounds good - within a very narrow volume range, and a very narrow range of speakers.  But at normal volume levels, even modest dynamics will send the amp into clipping.  You have no headroom.  If you like it, great, but for me, I need more power.



your correct the 45 tube'd SET's are only for the very hi sensitivity speakers like horns, but with the right speaker they are some of the best sounding amps I've heard. 2A3's as well.  I ran mine when i had them on 105db speakers and they were more then enough for full volume concert level listing if that's your thing. But very limited to those very hi efficiency speakers. 

I've had a Had "Firebottle" HO (high output...maybe 12 or so massive watts with my fave output tubes) for six or seven years and have used it (mostly) with a pair of very efficient Heresy IIIs. Not interested in any amp with less power really except maybe a Had 300b amp someday, driven by curiosity. I switch between the Had amp and a Pass XA-25 as my mood dictates so I'm pretty much covered amp wise, and absolutely love my gear heap...wait, I have to run into the next room and look at it...ahhh...

@wolf_garcia -- I haven't heard the 300 by Dennis, but a friend has one.  He said it is incredible.  

Yeah...saw one with the Western Electric tubes and thought...hmmm...love to hear it...pricey but way cool.

@wolf_garcia -- I also think it is not for the beginner in this hobby, but actually $4,000 is chump change compared to some of the amps I see for sale on this site.  A low-production, point to point wiring, handmade, signed and dated 300B amp made by Dennis Had?  $4,000 isn't that bad in the scheme of things.

Yeah his amps are world class and certainly on the level of the most exclusive Japanese stuff. My Firebottle was relatively cheap in 2017...one month used for maybe 1100 bucks. I also bought a used (newer) "Hotrod" version but is wasn't quite as punchy as my non-hotrod amp so I sold it. Simply amazing sounding stuff.

@wolf_garcia -- A BIG amen on the "simply amazing sounding".  On top of that, Dennis is very easy to reach via email AND he responds in a pretty quick time frame.  He also monitors the Forums specializing in his gear and answers questions and gives input quite frequently.  


I contacted him with a question about the Emission Lab tubes, and he responded in less than a day.  I had mentioned in my email that, "All I need to complete a wonderful setup was to find one of his Phono Preamps for sale somewhere", and he told me he was in the process of building a few new ones, and as a member of the "Had Family", he quoted me price almost $1,000 below the typical price.  I am jumping on that in a heartbeat!  That will be an awesome setup in one of my primary listening rooms!