Power Amps? The what the wherefore and why?

[AJ567]

On 07/05/2022 at 01:17, Nebadon2000 said:

 

Markbass has a parallel FX Loop when you plug into Return it does not bypass preamp just turn  any EQ knob LM III for confirmation.

But with LM III EQ settings at noon the flavor of your pedal will be dominant. 

 

I'd have thought series/parallel doesn't make a difference in this situation - if there is nothing plugged into the instrument input then there is no signal coming out of the preamp section? In any case, you can change it to series by moving an internal jumper (did it on mine when I had one, dead easy). 

 

The FX loop needs to be set to post-EQ, however, otherwise you are not bypassing the whole preamp and the EQ knobs will affect the sound as you describe. 

[AJ567]

On 05/05/2022 at 11:50, FarFromTheTrees said:

 

 

 

Would a power amp provide a cleaner tone for my BK7U & other FX than the LMIII?

 

Not if you bypass the preamp section of the LMIII (which is what you are doing by plugging into the FX return when it is set to post-EQ). 

 

The LMIII is a very good power amp that just happens to have a very good preamp in the same box. You can bypass the preamp, as you have discovered. 

 

Using a standalone power amp is a fairly niche route for people who are married to particular preamps and/or need way more power than a typical bass head can provide. Doesn't sound like you are one of those people!

[agedhorse]

On 06/05/2022 at 06:23, Happy Jack said:

I've had mixed experience with power amps from Thomann, including one that started emitting showers of sparks before catching fire in the middle of a country & western gig, but the most pleasant surprise I've had in ages was

 

https://www.ebay.co.uk/itm/334387167184?_trkparms=amclksrc%3DITM%26aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D238392%26meid%3D917a7f0b8ee44f5385317286705ce2b5%26pid%3D101195%26rk%3D1%26rkt%3D12%26sd%3D233645394188%26itm%3D334387167184%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DSimplAMLv9PairwiseWebMskuAspectsV202110NoVariantSeed&_trksid=p2047675.c101195.m1851&amdata=cksum%3A334387167184917a7f0b8ee44f5385317286705ce2b5|enc%3AAQAGAAABEIIp3bTCXFAKw6S9crk9CpCrrtOgadqFiC10NVPbN0936eprYVB4SXfDa52e1mbPLDW8ro3fGQu%2F2vb5HwnsBryEo8JPOIoqExMG2vjEAsrUdVOBhKTK4T80B%2BWjs2bT2tB6euVOgqWZ9Ah%2BmXDW3clgzpSDYvlCs9Y9Rl5rIf%2FOhXUr51CGcpwqh7RjNEvaJJmw4U0jRFEUAQ1glZiLUtqKm%2F1av%2FXPJe02AwJQxUQqurau3To8fZLhsvjhBqAulOLYXfFVBASw5G5zwAMAeTku42qZkCQ2JcFw0mFN3bdZaZLEdqB18uGsFREQMrsFpmGNdvZztNkUUkxgUQRRSYTaxn%2FSfCBgJrveldalupf6|ampid%3APL_CLK|clp%3A2047675

 

I bought the 2-channel 2600W 'New Generation' and I've been delighted with it. My default option for power amps is to buy ludicrously expensive Powersoft Digam units, so I keep an eye on the cheap clone market from the Far East. This was my fourth attempt at buying a cheap-as-chips lightweight 1U power amp from China and, if this one is anything to go by, they've finally cracked it.

 

With no legitimate safety approvals on any of these products, “shower of sparks” is a great example of “you get exactly what you pay for”.

[agedhorse]

On 06/05/2022 at 06:23, Happy Jack said:

I've had mixed experience with power amps from Thomann, including one that started emitting showers of sparks before catching fire in the middle of a country & western gig, but the most pleasant surprise I've had in ages was

 

https://www.ebay.co.uk/itm/334387167184?_trkparms=amclksrc%3DITM%26aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D238392%26meid%3D917a7f0b8ee44f5385317286705ce2b5%26pid%3D101195%26rk%3D1%26rkt%3D12%26sd%3D233645394188%26itm%3D334387167184%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DSimplAMLv9PairwiseWebMskuAspectsV202110NoVariantSeed&_trksid=p2047675.c101195.m1851&amdata=cksum%3A334387167184917a7f0b8ee44f5385317286705ce2b5|enc%3AAQAGAAABEIIp3bTCXFAKw6S9crk9CpCrrtOgadqFiC10NVPbN0936eprYVB4SXfDa52e1mbPLDW8ro3fGQu%2F2vb5HwnsBryEo8JPOIoqExMG2vjEAsrUdVOBhKTK4T80B%2BWjs2bT2tB6euVOgqWZ9Ah%2BmXDW3clgzpSDYvlCs9Y9Rl5rIf%2FOhXUr51CGcpwqh7RjNEvaJJmw4U0jRFEUAQ1glZiLUtqKm%2F1av%2FXPJe02AwJQxUQqurau3To8fZLhsvjhBqAulOLYXfFVBASw5G5zwAMAeTku42qZkCQ2JcFw0mFN3bdZaZLEdqB18uGsFREQMrsFpmGNdvZztNkUUkxgUQRRSYTaxn%2FSfCBgJrveldalupf6|ampid%3APL_CLK|clp%3A2047675

 

I bought the 2-channel 2600W 'New Generation' and I've been delighted with it. My default option for power amps is to buy ludicrously expensive Powersoft Digam units, so I keep an eye on the cheap clone market from the Far East. This was my fourth attempt at buying a cheap-as-chips lightweight 1U power amp from China and, if this one is anything to go by, they've finally cracked it.

 

With no legitimate safety approvals on any of these products, “shower of sparks” is a great example of “you get exactly what you pay for”.

[agedhorse]

On 06/05/2022 at 06:23, Happy Jack said:

I've had mixed experience with power amps from Thomann, including one that started emitting showers of sparks before catching fire in the middle of a country & western gig, but the most pleasant surprise I've had in ages was

 

https://www.ebay.co.uk/itm/334387167184?_trkparms=amclksrc%3DITM%26aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D238392%26meid%3D917a7f0b8ee44f5385317286705ce2b5%26pid%3D101195%26rk%3D1%26rkt%3D12%26sd%3D233645394188%26itm%3D334387167184%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DSimplAMLv9PairwiseWebMskuAspectsV202110NoVariantSeed&_trksid=p2047675.c101195.m1851&amdata=cksum%3A334387167184917a7f0b8ee44f5385317286705ce2b5|enc%3AAQAGAAABEIIp3bTCXFAKw6S9crk9CpCrrtOgadqFiC10NVPbN0936eprYVB4SXfDa52e1mbPLDW8ro3fGQu%2F2vb5HwnsBryEo8JPOIoqExMG2vjEAsrUdVOBhKTK4T80B%2BWjs2bT2tB6euVOgqWZ9Ah%2BmXDW3clgzpSDYvlCs9Y9Rl5rIf%2FOhXUr51CGcpwqh7RjNEvaJJmw4U0jRFEUAQ1glZiLUtqKm%2F1av%2FXPJe02AwJQxUQqurau3To8fZLhsvjhBqAulOLYXfFVBASw5G5zwAMAeTku42qZkCQ2JcFw0mFN3bdZaZLEdqB18uGsFREQMrsFpmGNdvZztNkUUkxgUQRRSYTaxn%2FSfCBgJrveldalupf6|ampid%3APL_CLK|clp%3A2047675

 

I bought the 2-channel 2600W 'New Generation' and I've been delighted with it. My default option for power amps is to buy ludicrously expensive Powersoft Digam units, so I keep an eye on the cheap clone market from the Far East. This was my fourth attempt at buying a cheap-as-chips lightweight 1U power amp from China and, if this one is anything to go by, they've finally cracked it.

 

With no legitimate safety approvals on any of these products, “shower of sparks” is a great example of “you get exactly what you pay for”.

[agedhorse]

On 06/05/2022 at 06:23, Happy Jack said:

 

Edited May 24, 2022 by agedhorse
Delete duplicate post

[BassmanPaul]

LOL

[Nebadon2000]

AJ567 SAID; "The FX loop needs to be set to post-EQ, however, otherwise you are not bypassing the whole preamp and the EQ knobs will affect the sound as you describe." 

 

How is this done?

 

Also someone posted he set jumpers inside to series and with MarkBass it still passed through preamp EQ.

[prowla]

On 06/05/2022 at 09:29, NancyJohnson said:

To support content here, until I went the pre/power route, I don't think any one head actually produced what I wanted tonally.  For years I used a variety of kit, Hartke (endorsed),Trace, SWR, Ashdown; none of this really gave me the dirty clank grunt I desired.  Light-bulb moment here was sticking a Bass POD into the effects return of an Ashdown MAG (cue angels singing).

 

Next thing was to reduce the size and weight of everything, so I filled a short 4U Gator rack with a Sansamp RBI, a Korg Tuner and a Matrix poweramp.  Heavenly,  That I could just carry one box it was just win/win.

 

(Despite my desire to go more lightweight/smaller, I eventually chopped all this in and went with a Darkglass AO900 head.  I like the power it provides, but tonally not so much, so I'm back to running a couple of @Tech21NYC stomps into the effects return.   If they'd make a GED head like that VT Bass 500 thing they made a while back, I'd just go with that.)

I just picked up an Ampeg valve pre-amp, which is just great. (I tried it through the Fx Return of a MarkBass.)

The problem is I now want a 2nd (for stereo).

I might pick up a SansAmp one to tide me over.

 

On 06/05/2022 at 11:08, Happy Jack said:

 

That's pretty much your answer there. No intention to be dismissive, but you're almost certainly wasting your time (and your money) if you go the preamp + power amp route. That's a solution (one of many) to issues encountered when playing live. If you do end up on stage, and it's amazing how often that's the outcome 😎, then re-visit this topic one you have a couple of dozen gigs under your belt.

I think the pre-amp can make a big difference even in a home setup.

 

On 06/05/2022 at 14:23, Happy Jack said:

I've had mixed experience with power amps from Thomann, including one that started emitting showers of sparks before catching fire in the middle of a country & western gig, but the most pleasant surprise I've had in ages was

 

https://www.ebay.co.uk/itm/334387167184?_trkparms=amclksrc%3DITM%26aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D238392%26meid%3D917a7f0b8ee44f5385317286705ce2b5%26pid%3D101195%26rk%3D1%26rkt%3D12%26sd%3D233645394188%26itm%3D334387167184%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DSimplAMLv9PairwiseWebMskuAspectsV202110NoVariantSeed&_trksid=p2047675.c101195.m1851&amdata=cksum%3A334387167184917a7f0b8ee44f5385317286705ce2b5|enc%3AAQAGAAABEIIp3bTCXFAKw6S9crk9CpCrrtOgadqFiC10NVPbN0936eprYVB4SXfDa52e1mbPLDW8ro3fGQu%2F2vb5HwnsBryEo8JPOIoqExMG2vjEAsrUdVOBhKTK4T80B%2BWjs2bT2tB6euVOgqWZ9Ah%2BmXDW3clgzpSDYvlCs9Y9Rl5rIf%2FOhXUr51CGcpwqh7RjNEvaJJmw4U0jRFEUAQ1glZiLUtqKm%2F1av%2FXPJe02AwJQxUQqurau3To8fZLhsvjhBqAulOLYXfFVBASw5G5zwAMAeTku42qZkCQ2JcFw0mFN3bdZaZLEdqB18uGsFREQMrsFpmGNdvZztNkUUkxgUQRRSYTaxn%2FSfCBgJrveldalupf6|ampid%3APL_CLK|clp%3A2047675

 

I bought the 2-channel 2600W 'New Generation' and I've been delighted with it. My default option for power amps is to buy ludicrously expensive Powersoft Digam units, so I keep an eye on the cheap clone market from the Far East. This was my fourth attempt at buying a cheap-as-chips lightweight 1U power amp from China and, if this one is anything to go by, they've finally cracked it.

 

That's interesting - I'm just looking at those; I've been thinking of the 4-channel one, so I can put synth pedals through it too. I'll probably go for one at the end of the month.

What depth rack case do they need?

I'm debating whether two 1U pre-amps plus one of those will work in a Chord 3U fabric case, or whether they'll need more room to breathe.

[Happy Jack]

7 minutes ago, prowla said:

What depth rack case do they need?

I'm debating whether two 1U pre-amps plus one of those will work in a Chord 3U fabric case, or whether they'll need more room to breathe.

 

Shallow. 

[prowla]

1 hour ago, Happy Jack said:

 

Shallow. 

Great - I may try them in the one here (pictured at the last SE Bass Bash).

 

A couple of these and one of those power amps should do the trick...

 

If that works, I'll get another of the same to put the synth units back in.

Edited May 28, 2022 by prowla

[Vin Venal]

On 05/05/2022 at 14:54, FarFromTheTrees said:

Just tried bypassing the preamp via the FX return as suggested and it sounds amazing. It makes quite the difference!

 

Now I'm considering selling my LMIII and getting a power amp instead haha.

If bypassing the preamp sounds better, before you change your gear, try changing the order of your effects by running some in the loop instead of in front of the amp.

 

That might sound even better, as the issue may be where the preamp sits in the signal chain rather than the preamp in itself if you see what I mean?

 

What effects do you run?

[AJ567]

On 28/05/2022 at 01:24, Nebadon2000 said:

AJ567 SAID; "The FX loop needs to be set to post-EQ, however, otherwise you are not bypassing the whole preamp and the EQ knobs will affect the sound as you describe." 

 

How is this done?

 

Also someone posted he set jumpers inside to series and with MarkBass it still passed through preamp EQ.

Pre EQ is the stock config. I thought it was switchable using internal jumpers... But possibly I have muddled it and it's not possible. In which case the FX return only bypasses the preamp gain and not the EQ. 

 

Best the OP can do is turn the VPF/VLE off and the EQ to noon. Should be pretty transparent.

[Lfalex v1.1]

When I was  gigging/ rehearsing, I used to use an Ampeg SVP-pro like the one in Prowla's second picture. Had it in a 4u rack with a Korg tuner and a QSC PLX1202 (bridged for maximum effect)

 

I always used to end up in 5- piece bands with hard-hitting drummers and 2 noisy guitarists. It'd be more controllable if everyone turned down, but you know how it is. The QSC was my commitment to mutually-assured-deafness. Everyone would tell at me to turn down, so I did. As lond as they did, too.

 

Pros- 

Power! (If you want it)

Flexibility 

Choice of mixing & matching pre/power amps

Some have features that heads may not have (extra channels, bridgeability, HFpass filters, limiters)

 

Cons-

Size

Weight

Complexity

Cost

 

 

 

 

 

[Nebadon2000]

On 29/05/2022 at 03:39, AJ567 said:

Pre EQ is the stock config. I thought it was switchable using internal jumpers... But possibly I have muddled it and it's not possible. In which case the FX return only bypasses the preamp gain and not the EQ. 

 

Best the OP can do is turn the VPF/VLE off and the EQ to noon. Should be pretty transparent.

 

I just read from someone who 'Allegedly' switched jumpers in LMIII and said it still did not bypass EQ; I have not ventured there yet with my MarkBass.

 

I agree with "Best the OP can do is turn the VPF/VLE off and the EQ to noon". Should be pretty transparent" but 'SparkyMark' has said parallel loop is 50/50 blend not sure how that will effect pedal/preamp other than having to crank volume to max and maybe a tad more on MarkBass.

 

I am going to try both effect loop and in front of amp when my SushiboxFx Space Heater arrives before venturing inside of amp searching for jumpers.

 

Be nice if MarkBass put a switch on back of amp. Parallel EFX Loop does have some advantages, one being you are not running original/clean signal threw Pedal/preamp and 2 extra cables at all times and if pedal fails doesn't shut down your sound mid Gig.

 

PS; I misunderstood your post at first read; now see that setting to 'post EQ' is setting to 'Series' using jumpers.

[prowla]

I'm going for one of the ones @Happy Jackrecommended; the 4-channel version (https://www.ebay.co.uk/itm/334387167184?var=543385789351) (there was also a code for an extra 5% off).

 

A word of warning - I looked at some options and some brands are (deliberately) vague as to what their Watts are; for example this one just says "2x 500W", without saying peak or RMS; after a bit of poking around I found a seller saying "max", so I guess that's peak then. https://www.ebay.co.uk/itm/184524818501

Edited June 3, 2022 by prowla