Bypass IR Loader on power soak?

[twotoedsloth]

Hey,

My partner has been asking for an electric guitar. I want to help her out, so I have a question. Anything but a tube amp is a non starter for her, and we live in an apartment complex, so we're going to need a power soak.

Is there a way to get a power soak that does not have an IR loader built in? She will probably want to avoid digital processing. Budget is probably $500-$750, no more though, as the amp itself is going to cost $1200 give or take.

Please let me know,

Peter

[ef37a]

https://www.thomann.co.uk/harley_benton ... 05c738bd43

Hi Peter, no idea how good the above is but I had to start somewhere!

It seems power soaks fall into two groups? Those that are purely resistive (I suspect that HB is one such) and those that incorporate some "speaker like" reactive elements, i.e. inductors. From what I glean from forums, some amps work better with one type than others but of course, like gitamps themselves, this is a massively subjective matter and dripping with snake oil.

One "constant" is that the load must be rated above the 'book' power of the amplifier. At least 50% over and I am happier with 100% (same goes for speakers BTW) The very last thing you want with your valve amp at fullish chat is for the load to burn out.

I am sure Wonks and others on the strength will have much valuable information. Also there is a chap called "ICBM" over at thefretboard.co.uk who is a very experienced amp tech and player and has had a lot of experience with power soaks with a variety of amps.

Dave.

[Wonks]

I don't have much to add. I have a basic Bugera (Behringer) resistive attenuator which does the quieting job fine, but leaves a lot to be desired in the tone and feel side of things.

At one point some years ago I believe the Palmer power soaks were about the best, but I'm sure there are better ones out there. Plus the maximum power reduction on those was to 18% of the input power, which may sound a lot but that's only a 7.4dB drop in level, or just under half the original volume.

A lot will depend on the power of the amp you are planning to get and whether it has a master volume or not. With a master volume and a fairly low powered amp, you can normally keep things as quiet as you need without a power soak.

Whilst people will wax lyrical about the sound of the power amp valves being pushed into distortion, personally I don't think it adds that much. You may prefer the sound of the amp at a quiet setting with a few good pedals in front than the amp pushed hard with a lot of attenuation (like a compressor and a mild good-sounding overdrive like a Timmy clone). And if you want a clean sound, just don't turn up the volume too much.

Whilst most combos will have a jack socket for an extension speaker, some don't. And some low-powered Fender vintage-style amps will have the speaker connection on an annoying RCA connector, which makes it very awkward to fit an attenuator in line with the speaker without using very specific adapter cables. And adapters reduce reliability and you don't want a valve amp running into an open circuit.

So think about that before selecting an amp.

Even for clean, you'll normally want to get the volume to a point where you are starting to get a bit of distortion from the preamp to make it harmonically interesting without being noticeably distorted. On an amp without a master volume, even this can be too loud for apartment use, even for relatively low powered amps e.g. 15W or more. What may sound like a quiet level in a store may be very neighbour unfriendly once you get it home.

Unless you plan to gig it (and remember she's got to learn to play the guitar first), a 5W amp with a 10" or 12" speaker will be more than sufficient to learn on.

[ef37a]

"Whilst people will wax lyrical about the sound of the power amp valves being pushed into distortion, personally I don't think it adds that much."

SO! Glad you wrote that Wonks! I know we have had..err. "moments" in the past but we seem to agree on that point. There is an awful lot of BS spoken about "valve sound" from output stages. In fact, as Wonks states, most of the overdrive tone from a valve amp comes from the pre amp.

That is not to say you can just exchange a 50W OP valve stage with a hefty class D device, no, valves have a particular way of interacting* with speakers (in guitar amps) which is almost impossible to duplicate with SState devices, though some designs come close but this interaction has more to do with the frequency response of the amplifier/speaker and not the distortion.

Then a few simple sums show the illogic of these magical OP stages? A pair of EL84s will deliver about 15W at maybe 5% distortion. Now, 5%THD will cause Dr Hugh to go green but in this context, 5% is barely detectable. By the time the output stage is producing noticeable grunge it is close to clipping and you have run out of power. In other words, OP stage distortion is a very narrow "sweet spot". Of course, even 15W is excruciatingly loud at some 112dB/mtr SPL from any decent guitar speaker.

*Actually it effectively doesn't interact, it tends to leave the speaker to 'do its own thing'.

Dave.

[Sam Spoons]

It would be much easier to buy a low powered amp for home use and, later, a bigger amp for gigging if/when that becomes a priority. The Thomann list below has sub 6 watt valve amps from £125 to £2333. Choosing the right one will depend on the styles of music she want's to play but 5 watts can be loud so if one of the options that include low power modes might be best.

The Blackstar HT1 would be a good choice for distorted genres or a 5 watt with a 10" or 12" for blues or indie sounds. I much prefer 10" or 12" speakers to 8" but I like more old school sounds even when playing with distortion, more Clapton or Santana than Meggashugga (no scooped mids and screaming treble for me).

$1200 for a 'bedroom' amp sounds like a lot of money, are your looking a giggable amp straight away? If so I'm guessing she already plays acoustic guitar to a decent standard and is looking to go electric?

https://www.thomann.co.uk/tube_guitar_c ... ilter=true

[ef37a]

Thing is Sam, even 5 watts is very loud in a domestic setting, well over 100dB and until we know Peter's circumstances, more precisely how loud his good lady can play, it is hard to suggest an amplifier and if valves are non-negotiable, a power soak might be the only solution. Mind you, if we take 15W (valve) as the bare minimum for gigging, smashing that down to mWs so as to keep next door happy will do the "tone" no good at all.

I shall however shamelessly suggest the HT-5. This amp is AFAIK unique in having a fixed biased, push pull OP stage. The result of that is just about 5W of clean sound but give it the beans and it will chuck out 10 watts. That is something none of the single ended, EL84/6V6 amps can do and it makes the HT-5 viable (just) for small venue gigging. I have heard one through a 340W 4x12 and it looks stupid sat atop the cab but sounds devastating!

The HT-5 also has a very good reverb in it, FX loop (with +4dBu levels) emulated out, headphone out and has about the best noise floor of any guitar amp on the planet i.e. makes it a great studio amp.

Dave.

[Wonks]

The original HT5 was great, but the mk 2 HT5R was a definite backward step in sound for me. I gave mine away and kept the original HT5 combo (one of the first batch to arrive from China).

[ef37a]

The original HT5 was great, but the mk 2 HT5R was a definite backward step in sound for me. I gave mine away and kept the original HT5 combo (one of the first batch to arrive from China).

Well,being mutton I don't really have an opinion but I preferred the original setup where the tone stack was common to both channels.
And I am pretty sure those early ones were made in S Korea?

Can you remember what you didn't like Wonks? Voicing? OD character?

Dave.

[Sam Spoons]

I sold my HT5*, it was great but didn't really suit the styles I was playing as well as my Epiphone Valve Junior** (though I much preferred the 12" speaker to the dodgy 8" in the VJ). But the HT5 does have low power modes which may well be useful.

If valves are non-negotiable then a small amp with power scaling of some kind might be a better option than an external power soak. But we don't know yet if this is for home practice only or needs to be giggable. If it's for home only then see if you can persuade her to give some solid state amps a listen***, even if only to confirm that they don't work for her.

* I can't remember if it was to fund the purchase of a Boogie mk4 or the building of my 18 watt combo.

** I did use the VJ on a low profile live gig once, unmiked, and it certainly didn't do clean but I did get away with it.

*** I'm a confirmed valve head but modern solid state/digital stuff is extremely good.

[Wonks]

The original HT5 was great, but the mk 2 HT5R was a definite backward step in sound for me. I gave mine away and kept the original HT5 combo (one of the first batch to arrive from China).

Well,being mutton I don't really have an opinion but I preferred the original setup where the tone stack was common to both channels.
And I am pretty sure those early ones were made in S Korea?

Can you remember what you didn't like Wonks? Voicing? OD character?

Dave.

Certainly the in first container load for somewhere in Asia. Went to the Blackstar stand at the London Guitar Show shortly after I got it to say how impressed I was (the other guitarist in the band got one after he heard mine) and what a great sound for the money and whoever I spoke to said yes, they didn't have a clue how to price them, so they took a guess at £199 (IIRC). This was back in 2008.

On the later HT-5Rc I didn't like the clean channel just having the basic tone knob. Nothing like as useful as using the common B/M/T controls of the Mk 1. I never felt that the EQ settings for the distortion channel were totally wrong for the clean channel (or vice versa), I could easily live with teh same for both.

And the distortion channel just didn't sound the same. It was OK, but it wasn't the same as the Mk1.

I know other people who just tried the Mk 2 HT5 said it sounded bad compared to other amps then available (it was quite ground breaking at the time), and I told them to look for a used Mk 1 instead.

The HT-5R reverb sounded OK to me and was the only real improvement made. I know it wasn't 'springy' enough for some, but I don't like my guitar sounds all dripping and boingy and prefer using a smooth plate-style reverb if possible.

[ef37a]

Hmm...I wonder? The very first Fives had a problem (well, several actually but soon sorted) and one was "farting out". This effect only happened with a really hot pickup and if mains voltage was a bit low, there was a bit too much gain in part of the circuit and the fix was a simple resistor swap.

However, if you weren't driving the amp SO hard and your juice was up to snuff you might have found the extra gain and resultant OD tone rather nice?

But you can't bloody win in the gitamp game! You liked the HT-5 MK1 but many slated it for its 10" Celestion speaker. Yes, it was a "hybrid" and we were never allowed to forget that! Does not seem to have done B's much harm though? I think this is the third recession they have come through?

The tiny HT-1 seems to be liked by just about everyone?

Dave.

[Wonks]

I had the bias transistors fail but replaced them and then rebiased it myself. Never suffered from 'farting out' (on the amp anyway).

And an HT5 head was certainly a lot louder through Rick Atkin's custom made 4x10" cab than my 15W Tiny Terror head through a Marshall 1x12" cab when we had a session at Max's Shonk studios (though it was a very expensive and substantial 4x10" cab).

[ef37a]

I had the bias transistors fail but replaced them and then rebiased it myself. Never suffered from 'farting out' (on the amp anyway).

And an HT5 head was certainly a lot louder through Rick Atkin's custom made 4x10" cab than my 15W Tiny Terror head through a Marshall 1x12" cab when we had a session at Max's Shonk studios (though it was a very expensive and substantial 4x10" cab).

What do you mean by "bias transistors" Wonks?

I would also like to add that Blackstar's published power ratings were sine power into 8 Ohms and with a carefully set 230V mains supply. Many people still get 240V and higher and so an HT-5 could probably hit 15W if pushed very hard.

Dave.

[Wonks]

Not sure if thats the correct term but there were two largish three-leg flat chips that were involved somewhere in the circuitry around where you set the bias and balance. The ones that fail a lot.

[twotoedsloth]

Thanks so much for all of your replies, I greatly appreciate it. It's the whole "buy smart, buy once" kind of thing.

My partner has a PhD in piano performance, but she has never played guitar, so gigging isn't really an issue just yet. However, she has quite a discerning ear, so she won't be happy with an entry level rig.

I was thinking of the Marshall Studio 900. It has a <1 watt mode, which might be good enough for apartment use, and might not require a power soak.

The guitar is a whole other world to sort through, I will probably have to impose further on this thread for advice, but I'm still researching at the moment.

Many thanks,

Peter

[Philbo King]

I had no idea that power soaks now have impulse response convolvers (assuming that IR doesn't mean infrared ). How do they power the convolver circuit?

I still use an Altair attenuator from the mid-70s, which can dial from 0 to -40 dB in 4 dB steps. It has been in the hack of my '65 Vibrolux Reverb amp for decades.

[Sam Spoons]

The IR Loader in some (not all) modern power soaks won't affect the speaker output anyway only the DI output so if you just want to quieten down a 'too loud' valve amp they will still do the job without the IR having any affect on the sound in the room.

WRT amps have you considered the Marshall DSL5CR as a more apartment friendly version of the Studio? It's 5 watts, all tube and has a 0.1 watt setting (so effectively a built in power soak) and only cost about ¼ of the price of the Studio 900? There is a DSL1CR too but it has a 8" speaker which would rule it out for me but get her to a guitar shop and give them a listen.

Oh, and decide on the guitar first, that, IMHO, is more important than the amp but the best amp to use with a Strat might be different to the one you'd choose if you have a Les Paul.

[ef37a]

Not sure if thats the correct term but there were two largish three-leg flat chips that were involved somewhere in the circuitry around where you set the bias and balance. The ones that fail a lot.

Ah, I think you mean the power MOSFETs that comprise the Phase Inverter? IRF830 IIRC. Yes, that part of the circuit did give problems, came down to 'tracking' between the device pins* and the fix was to cut slots with a fine Dremel saw.

That was a part of the circuit that the detractors fixated upon as well! The fact was that it had a CC transistor in its "tail" and was very transparent.

What the ignorant rabble also did not understand is that the conventional cathode coupled PI has ~50%NFB and thus is also very linear and contributes very little to the OD tone of "all valve" amplifiers. And while we are here? The other mod' was in the headphone circuit. The transistor controlling the muting FET would sometimes kill the feed to the PI and hence OP valve. The fix was to increase the base current of the transistor and thus up its gm.

This is of course all sorted by now!

*Oh! The things that **** you about like PCB and resistor resists NOT being as insulating as you expected them to be!

Dave.

[twotoedsloth]

In the interests of obviating the power soak, what would you think of using a Marshall DSL1HR 1amp/0.1amp head with a Marshall SC112 cabinet?

At work, I really prefer the sound of a 12 inch speaker, though I mostly record Jazz (and classical, but that does not use amplification!)

My awesome idea is to buy a good 1x12 cabinet that she can keep when the time comes to upgrade the head.

Am I on the right track?

Peter

[Wonks]

Let’s start with the type of music you/she wants to play. Clean or distorted?

[twotoedsloth]

Hello Wonks, I greatly appreciate you taking an interest.

My partner is likely to play a lot of heavily distorted tones - think Rise Against or Muse. I suspect this is a reaction to playing mostly the likes of Schumann and Faure at her real job.

Many thanks,

Peter

[Sam Spoons]

The 1 watt Marshall or Blackstar combos might be the sweet spot then, DSI1CR or HT1. Both are designed for heavy sounds at low volume.

[twotoedsloth]

Hello kind folks,

One more thing before I think we can put this thread to bed:

Is it a good idea to buy a Marshall DSL1HR head with a good 12 inch cabinet?

As I mentioned, this would give her the tube amp she's asking for, and then she can upgrade the head for a lower price than a whole new combo.

Many thanks,

Peter

[Sam Spoons]

Yes, that would be a good, and cost effective, idea, 12" (and 10") speakers almost always sound much better than 8" speakers like the one in the DSL1CR combo.

[twotoedsloth]

Okay Sam,

Many thanks. I will place the order for Marshall SC112 cabinet and DSL1HR right away.

Now, to figure out which guitar to get her...

Happy Monday gentlemen,

Peter