Jaybeevee Posted January 31, 2023 Share Posted January 31, 2023 (edited) Hi Folks, I recently picked up an amp (hybrid) class A/B that clipped when I cranked the master volume. Should that happen? I was pushing the (tube) pre amp a bit, and then to get it up to loud drummer volume, I up´t the volume to 12 o'clock and was getting clipping light flashing with a horrid distortion which accompanied the clipping light. Sounded like the cab was farting. I always thought (assumed) clipping was associated to the pre amp. Is it normal or knackered? Cheers Edited January 31, 2023 by Jaybeevee Quote Link to comment Share on other sites More sharing options...
Bill Fitzmaurice Posted January 31, 2023 Share Posted January 31, 2023 It depends on where the lamp is wired to the circuit. Clipping can take place at every stage of amplification, from the input to the output. The manual should say. In general minimal clipping takes place when the master is on full, with the pre volume low. 1 Quote Link to comment Share on other sites More sharing options...
Downunderwonder Posted January 31, 2023 Share Posted January 31, 2023 Maybe the cab was getting farty at the same time. No idea if it's broken or simply not enough rig for the situation. If the amp isn't broken I expect you need more cab. Most amps these days have plenty of power for rehearsals at least 1 1 Quote Link to comment Share on other sites More sharing options...
warwickhunt Posted January 31, 2023 Share Posted January 31, 2023 So you had the input/preamp pushed AND you had the master cranked... that pretty much says clipping is going to occur somewhere! Quote Link to comment Share on other sites More sharing options...
warwickhunt Posted January 31, 2023 Share Posted January 31, 2023 What is the amp? Quote Link to comment Share on other sites More sharing options...
Jaybeevee Posted January 31, 2023 Author Share Posted January 31, 2023 2 minutes ago, Downunderwonder said: Maybe the cab was getting farty at the same time. No idea if it's broken or simply not enough rig for the situation. If the amp isn't broken I expect you need more cab. Most amps these days have plenty of power for rehearsals at least Cabs are good for the amp. In terms of Watts the amp is's delivering towards the lower of the recommended range, and I run a more powerful amp at higher volumes. It was a circuit/electrical kind of distortion sound. hard to describe, but it sounded like the amp was at fault. I just never seen or realised clipping could be produced from master volume control. I will add that in terms of settings, the amp should have coped I feel. Quote Link to comment Share on other sites More sharing options...
Jaybeevee Posted January 31, 2023 Author Share Posted January 31, 2023 6 minutes ago, warwickhunt said: So you had the input/preamp pushed AND you had the master cranked... that pretty much says clipping is going to occur somewhere! A bit loosely described. I had the gain at about 2óclock to where the amp identifies ´crunch´. The amp also has a drive button providing 6db more to the tubes. With my Stingray I was getting some nicely mild overdriven tones.. point being well within the design intent of the amp. Then I tried to up the master to match the drummer. So I´m expecting all to be good. The master was set at around 11 clock when the clip light and distorted signal break up occurred. Again, if it's not hitting rehearsal volumes at these settings I´m suspecting an issue with the amp. I was just looking to get confirmation of that or some learning. 400W Mos Fet Transformer power supply should easily handle what I was asking of it. I was just wondering if clipping from the master is expected or un expected. Quote Link to comment Share on other sites More sharing options...
Jaybeevee Posted January 31, 2023 Author Share Posted January 31, 2023 20 minutes ago, Bill Fitzmaurice said: It depends on where the lamp is wired to the circuit. Clipping can take place at every stage of amplification, from the input to the output. The manual should say. In general minimal clipping takes place when the master is on full, with the pre volume low. Thanks, that's something new for me. Unfortunately, not supplied with a manual, and the manufacturer is not answering me specifically on this point. Quote Link to comment Share on other sites More sharing options...
Downunderwonder Posted January 31, 2023 Share Posted January 31, 2023 What cab load was on the amp? Quote Link to comment Share on other sites More sharing options...
Jaybeevee Posted January 31, 2023 Author Share Posted January 31, 2023 12 minutes ago, Downunderwonder said: What cab load was on the amp? 2 8ohm 112s, TKS 1126s to be precise. Amp is 400w @ 4ohms. My Main Amp is 500w @4ohms and is thunderous Quote Link to comment Share on other sites More sharing options...
Bill Fitzmaurice Posted January 31, 2023 Share Posted January 31, 2023 1 hour ago, Jaybeevee said: Thanks, that's something new for me. Unfortunately, not supplied with a manual, and the manufacturer is not answering me specifically on this point. You can find third party sources for manuals for most amps. Google ' *** amplifier manual'. 1 Quote Link to comment Share on other sites More sharing options...
Downunderwonder Posted January 31, 2023 Share Posted January 31, 2023 Load is fine, 500w v 400w isn't hardly any different, so seems like it's duff alright. Other thing to consider is your hookup cables and connections could be different. One funky miswired connector/ cable can put it out of phase so you're chasing your tail trying to get loud. 1 Quote Link to comment Share on other sites More sharing options...
Jaybeevee Posted February 1, 2023 Author Share Posted February 1, 2023 7 hours ago, Downunderwonder said: Load is fine, 500w v 400w isn't hardly any different, so seems like it's duff alright. Other thing to consider is your hookup cables and connections could be different. One funky miswired connector/ cable can put it out of phase so you're chasing your tail trying to get loud. Never thought of that. In my case same cables between both amps, but its a good bit of wisdom. Thanks Quote Link to comment Share on other sites More sharing options...
Downunderwonder Posted February 1, 2023 Share Posted February 1, 2023 23 minutes ago, Jaybeevee said: Never thought of that. In my case same cables between both amps, but its a good bit of wisdom. Thanks All same connections made on the cabs? One duff wired cab jack that was never used before would do it. 400w is pretty big for an old school SS amp. I wonder if it might be 200 + 200 with attendant switching that needs to be correct for the load. Quote Link to comment Share on other sites More sharing options...
Downunderwonder Posted February 1, 2023 Share Posted February 1, 2023 Problem solving in the blind outside the square since ages ago. Quote Link to comment Share on other sites More sharing options...
BassBunny Posted February 1, 2023 Share Posted February 1, 2023 15 hours ago, warwickhunt said: What is the amp? Very hard to offer any advice or opinion without knowing the amp in question. 1 Quote Link to comment Share on other sites More sharing options...
Jaybeevee Posted February 1, 2023 Author Share Posted February 1, 2023 8 hours ago, Downunderwonder said: All same connections made on the cabs? One duff wired cab jack that was never used before would do it. 400w is pretty big for an old school SS amp. I wonder if it might be 200 + 200 with attendant switching that needs to be correct for the load. 2 hours ago, BassBunny said: Very hard to offer any advice or opinion without knowing the amp in question. It's a new build from a small manufacturer. To be honest I´m not comfortable with saying what manufacture as it may not be a fault or I maybe misrepresenting something. I was really only trying to understand if master volume affecting clipping was a thing as I was sitting mulling it over and thought a quick post here might enlighten me. I got an answer to that early in the thread. The manufacturer is supporting me, so I see what's what after I get a replacement. Cheers though Quote Link to comment Share on other sites More sharing options...
Phil Starr Posted February 1, 2023 Share Posted February 1, 2023 19 hours ago, Jaybeevee said: The master was set at around 11 Never set the master to 11 😀 Joking aside the ‘clipping’ light doesn’t mean the same thing in different amps. They can be there to tell you if the input stage is just starting to go inti drive, if the compression is active or if the amp power stage is overloading, just as Bill said. The fact you heard the distortion and described it the way you did suggests the latter. 400W should be loud enough for any sensible rehearsal, unless you were usin g a lot of bass boost and cutting the mids? 1 Quote Link to comment Share on other sites More sharing options...
Jaybeevee Posted February 1, 2023 Author Share Posted February 1, 2023 Well I guess I was, where as i was using my Stingray 2 eq wide open. With respect to a 77 Stingray eq, they are bass treble cut n boost despite no centre indent. So yeah. It is how I always play it though and again I was A/B testing against my current amp (similar in power, solid state transformer etc). I didn't have a passive bass to hand to see if the clipping was occurring at similar levels. And here is another thing. This particular amp is made or fitted with linear pots. Where as most amps deliver more power in the early part of the volume sweep, and much less in the later, this amp delivers a linear power based on the pot adjustment. As mine was clipping at 11 (o'clock) this is less than half the full power. In any case, the builder thinks it may have taken a knock in transit. So i´m hoping that is the case. There is not Active/passive input switch, and so I hoping there isn't an inherent problem with this amps suitability to active basses. I have actually read a comment by an active player who had similar issues with this amp, so we see when I get a replacement.. Thanks for the input. Quote Link to comment Share on other sites More sharing options...
Downunderwonder Posted February 1, 2023 Share Posted February 1, 2023 A couple of things. You couldn't get a good tone without the amps +6dB engaged? What happens if you forgo that and turn up the Master Vol? I wonder if your regular amp has a much more effective high pass filter than the new one. 1 Quote Link to comment Share on other sites More sharing options...
Jaybeevee Posted February 1, 2023 Author Share Posted February 1, 2023 14 minutes ago, Downunderwonder said: You couldn't get a good tone without the amps +6dB engaged? What happens if you forgo that and turn up the Master Vol? Yeah, sure I could, but I was giving it a run. I wanted to test and hear various settings. I used the per-amp features in this case to get a nice not to dirty overdriven tone, and once found that, I wanted it loud enough to play with the drummer. The amp wouldn't deliver this without clipping. The high pass thing.. gawd knows.. Quote Link to comment Share on other sites More sharing options...
Bill Fitzmaurice Posted February 1, 2023 Share Posted February 1, 2023 1 hour ago, Jaybeevee said: This particular amp is made or fitted with linear pots. Where as most amps deliver more power in the early part of the volume sweep, and much less in the later, this amp delivers a linear power based on the pot adjustment. Seems like a good idea, but our hearing isn't linear with respect to power. It's logarithmic, requiring ten times the power to sound twice as loud. That's why logarithmic taper pots are used for volume controls. They may not be linear, but they sound linear. 2 Quote Link to comment Share on other sites More sharing options...
Downunderwonder Posted February 1, 2023 Share Posted February 1, 2023 39 minutes ago, Jaybeevee said: nice not to dirty overdriven tone One man's nntdot is another's raging inferno. What I asked was if you had any success amping it up without the 6dB on. Hopefully both amps have a series FX loop. Put bass into one amp and take the preamp out to the other amp's return, and on to the cabs. Play with gains to see if it's still impossible to get volume. Quote Link to comment Share on other sites More sharing options...
agedhorse Posted February 2, 2023 Share Posted February 2, 2023 Knob position has nothing to do with how much power is being delivered. This misunderstanding may be part of the problem. is the clip LED indicating input/preamp clipping or power amp clipping? Quote Link to comment Share on other sites More sharing options...
BassmanPaul Posted February 2, 2023 Share Posted February 2, 2023 @Downunderwonder I hope you're keeping your feet dry my brother. 1 Quote Link to comment Share on other sites More sharing options...
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