Since my UK Custom Shop LB 30 (Mk2) appears to be built a bit different than the original (Mk1), I decided to pick up this one: SOLD - Ashdown Little Bastard
Just got through playing both amps and here are my impressions.
The basic voicing of both amps is pretty similar. The Mk1 seems a bit looser and more woolly. You might think of it as more vintage sound. The Mk2 has really round, but clear and focused lows. You might think of it as more modern. You can dial a lot of lows into the Mk1, but I believe you can dial even more heft and slam into the Mk2.
Tone Controls:
Headroom:
In trying to figure out what was going on with the LB 30 Mk2, I also noticed that there are at least two versions of the CTM 30. My understand is the CTM 30 was the same circuit as the LB 30. This may be true with the original LB 30 and CTM 30, but the 20th AV CTM 30 appears to be a bit different. The Bass and Middle rotary tone controls are reversed like on the LB 30 Mk2, but the Bass and Middle switches are not reversed. I have no way to determine if the 20th AV CTM 30 is the same circuit as the LB 30 Mk2, the LB 30 Mk1, or a third circuit. However, the 20th circuit board appears visibly different than both LB30s and the original CTM 30. I guess it will have to remain a mystery as I don't plan to buy a CTM 30 and CTM 30 20th AV. However, I may be tempted to buy a CTM 30 Little Stubby and also an Ampeg PF-50t. Yes I know
rollno.
Just got through playing both amps and here are my impressions.
The basic voicing of both amps is pretty similar. The Mk1 seems a bit looser and more woolly. You might think of it as more vintage sound. The Mk2 has really round, but clear and focused lows. You might think of it as more modern. You can dial a lot of lows into the Mk1, but I believe you can dial even more heft and slam into the Mk2.
Tone Controls:
- The tone controls (rotaries and switches) in the Mk1 behave exactly as I expected them to. All controls have a noticeable affect on the sound. Bass Shift Scoops out the mids and Mid shift changes the upper knee of the Bass Rotary control. Bright does exactly what it sounds like on both amps, although the change is very subtle IMHO. I would say the controls in the Mk1 or more effective.
- As I mentioned previously the controls on the Mk2 do not work as I originally expected because the circuit appears to be a bit different. The bass rotary on the Mk2 is really dominant, and the mid control has very little effect. The switches also work a bit different. I believe the function of the Mid Freq switch is similar to the Mid Shift on the Mk1, but the change it imparts is a bit different. In one position the knee of the bass control is shifted so high that it does not matter how you adjust the Mid rotary. I believe the Bass Freq switch changes the HPF (where the low end rolls off). But the effective HPF for both positions is so low I can't hear a difference. However, when the amp is pushed slightly into drive, the switch seems to have an impact on how compressed the sound is. The controls may be less effective in the Mk2, but I think I like the way it sounds a bit better.
- As I mentioned previously the controls on the Mk2 do not work as I originally expected because the circuit appears to be a bit different. The bass rotary on the Mk2 is really dominant, and the mid control has very little effect. The switches also work a bit different. I believe the function of the Mid Freq switch is similar to the Mid Shift on the Mk1, but the change it imparts is a bit different. In one position the knee of the bass control is shifted so high that it does not matter how you adjust the Mid rotary. I believe the Bass Freq switch changes the HPF (where the low end rolls off). But the effective HPF for both positions is so low I can't hear a difference. However, when the amp is pushed slightly into drive, the switch seems to have an impact on how compressed the sound is. The controls may be less effective in the Mk2, but I think I like the way it sounds a bit better.
Headroom:
-The Mk2 seems cleaner, but not necessarily louder. I can run the tone controls completely CW and the preamp remains clean. The output section also seems a bit cleaner. This amp idles at 84mA on my variac. It's running a set of JJ EL84s that are probably the original tubes.
- If I turn up the tone controls on the Mk1 beyond about 9:00, the preamp develops drive. The output section also seems to break up a bit easier. It idles at 92mA, so the two sets of output tubes are probably not biasing the same. This amp is running a set of Ruby EL84s. Not certain, but I think the Mk1 way be a bit more compressed sounding as well.
- As they are currently operating, the Mk1 is better for distortion and the Mk2 is better for clean.
Noise:- If I turn up the tone controls on the Mk1 beyond about 9:00, the preamp develops drive. The output section also seems to break up a bit easier. It idles at 92mA, so the two sets of output tubes are probably not biasing the same. This amp is running a set of Ruby EL84s. Not certain, but I think the Mk1 way be a bit more compressed sounding as well.
- As they are currently operating, the Mk1 is better for distortion and the Mk2 is better for clean.
-The Mk2 is pretty much dead silent.
-The Mk1 seems to have some residual hum, but it is very low level. You won't hear it unless you put your ear right next to the speaker.
- The difference could be matching in the output tubes, or it could be because the Mk2 has a choke which filters out more of the noise.
Appearance:-The Mk1 seems to have some residual hum, but it is very low level. You won't hear it unless you put your ear right next to the speaker.
- The difference could be matching in the output tubes, or it could be because the Mk2 has a choke which filters out more of the noise.
-The Mk1 has vents on the top and side of the case and the light in the meter is a bit dimmer. The meter seems less sensitive. The amp starts to distort before the meter hits 0dB and with the amp fully cranked the meter is less likely to hit the end stop.
-The Mk2 does not have vents on the top and side of the case. The light in the meter is brighter. The meter seems significantly more sensitive. The meter hit 0dB right when the amp starts to distort, and if you really crank the amp the meter repeatedly hits the end stop.
I don't know if these amps are running the original preamp tubes, or how much use either amp has endured. The tone and headroom differences could be attributed to different or worn tubes, but tubes are not responsible for the different way the tone controls function.-The Mk2 does not have vents on the top and side of the case. The light in the meter is brighter. The meter seems significantly more sensitive. The meter hit 0dB right when the amp starts to distort, and if you really crank the amp the meter repeatedly hits the end stop.
In trying to figure out what was going on with the LB 30 Mk2, I also noticed that there are at least two versions of the CTM 30. My understand is the CTM 30 was the same circuit as the LB 30. This may be true with the original LB 30 and CTM 30, but the 20th AV CTM 30 appears to be a bit different. The Bass and Middle rotary tone controls are reversed like on the LB 30 Mk2, but the Bass and Middle switches are not reversed. I have no way to determine if the 20th AV CTM 30 is the same circuit as the LB 30 Mk2, the LB 30 Mk1, or a third circuit. However, the 20th circuit board appears visibly different than both LB30s and the original CTM 30. I guess it will have to remain a mystery as I don't plan to buy a CTM 30 and CTM 30 20th AV. However, I may be tempted to buy a CTM 30 Little Stubby and also an Ampeg PF-50t. Yes I know
rollno.
Although any setup with more than one kinda makes me drool!
