Photos of the included Accessories AND REAR of the equipment, please!

General Discussion Forum - Voice The Sound In Your Head
gt_jumper
Posts: 320
Joined: Sun Apr 11, 2010 12:00 am
Location: Queensland Australia

Wed Jun 30, 2010 9:37 am

pacAir wrote:Well, it looks like I will not get a chance to look at the Footswitch circuit for the HT60 Soloist anytime soon. The damaged/failed amp I thought I bought arrived today. The box was labeled HT-60 Soloist. Inside the box was an HT Club 40.

While I was disappointed (as I was looking forward to the foot-switchable solo boost) I will fight to get some money back on the deal. I intend to keep the amp since it was such a great deal (and it is already here). The amp was billed as having a dead Gain channel (which it did... all 7 knobs did absolutely nothing although the clean channel apparently works).

I took the back panel off and took a look around. The size of the transformers certainly concerned me... they really ought to be about twice as large as they are. I noticed that one of the preamp tubes didn't look right so I pulled it. This tube lost its vacuum and is no doubt the reason why there is no signal getting through the Gain channel! I'll pop a new one in tonight and I'll bet the amp works fine!

If it looks 100% I'll take it out (along with the matching HTV-112 cab I also got) tomorrow to play an outdoor gig. No sense in not trying it out right away. I hope "the stack" sounds as good as it looks!


Steve
Inspiring positive thinking there, keep us posted how you go, especially if its a happy ending.

pacAir
Posts: 39
Joined: Wed Jun 23, 2010 12:00 am

Wed Jun 30, 2010 8:23 pm

I replaced the bad tube and the HT Club 40 took off and worked great! I checked the bias and everything looks extremely good with no further attention required. The wiring, board layout, construction and component selection are quite good and quite a surprise at this price point. Even all the hardware was tight (this is not as common as you might believe in Asian-made amps now days)! This appears to be a well made amp despite the few obvious corners that were cut to make it more affordable (transformers, power supply, cabinet, speaker)!

Image

The amp sounds marvelous (just a little thin, due to the speaker) in both channels and the wide variety of tones you can achieve is astounding. It didn't take me long to dial in great clean tones and awesome gain tones reminiscent of my modified Marshall JCM800 combo (with added boost and gain). Since the amp appears to be solid I decided to play it at a gig this evening. The only modification I wanted to do was to try a "meatier" speaker with it. I had a pair of brand new Avatar Hellatone 60L (16-ohm) speakers (a Celestion Vintage 30 variant with more low-end grunt & pre-broken in).

Image

After installing the Hellatones in both the HT Club 40 and HTV-112 cabinet I took it for a spin. The Hellatones add more low-end authority and the 212 "stack" starts to approach the "beef" of a 4x12 in this regard. The HTV-112 cab sounds like it has more bass output than the combo but this may be because of the proximity to the floor when stacked.

Image

A few interesting design features I noticed: The amp appears to have both a Bias adjustment pot AND a balance pot to allow you to balance the tube's bias at precisely the level you want. Also, the Standby switch does NOT remove B+ high voltage (400Vdc) from the output tube plates as is traditional in most amps, it puts the tube in "cut-off" by more than doubling the negative bias voltage on the first grid (pin 5) from -31Vdc to -72Vdc. Another twist is that when you remove the input jack the amp automatically goes into the standby mode until you plug back in. This makes the amp absolutely quiet with nothing plugged into the input jack. This also means that you HAVE to insert a 1/4" plug into the input jack in order to bias the output tubes! Notice the attention to detail: Rubber O-rings in the chassis holes where the 12AX7 tubes are mounted and similarly isolated and padded EL34 tube retainers:

Image

Oh, here is a photo of the footswitch to keep this post on-topic!

Image

Anyway, this is an awesome amp at first look and I'll see how she does at this outside gig this evening.


Steve

jshaffer23
Posts: 186
Joined: Sun Jun 13, 2010 12:00 am

Wed Jun 30, 2010 8:48 pm

pacAir wrote:I replaced the bad tube and the HT Club 40 took off and worked great! I checked the bias and everything looks extremely good with no further attention required. The wiring, board layout, construction and component selection are quite good and quite a surprise at this price point. Even all the hardware was tight (this is not as common as you might believe in Asian-made amps now days)! This appears to be a well made amp despite the few obvious corners that were cut to make it more affordable (transformers, power supply, cabinet, speaker)!

Image

The amp sounds marvelous (just a little thin, due to the speaker) in both channels and the wide variety of tones you can achieve is astounding. It didn't take me long to dial in great clean tones and awesome gain tones reminiscent of my modified Marshall JCM800 combo (with added boost and gain). Since the amp appears to be solid I decided to play it at a gig this evening. The only modification I wanted to do was to try a "meatier" speaker with it. I had a pair of brand new Avatar Hellatone 60L (16-ohm) speakers (a Celestion Vintage 30 variant with more low-end grunt & pre-broken in).

Image

After installing the Hellatones in both the HT Club 40 and HTV-112 cabinet I took it for a spin. The Hellatones add more low-end authority and the 212 "stack" starts to approach the "beef" of a 4x12 in this regard. The HTV-112 cab sounds like it has more bass output than the combo but this may be because of the proximity to the floor when stacked.

Image

A few interesting design features I noticed: The amp appears to have both a Bias adjustment pot AND a balance pot to allow you to balance the tube's bias at precisely the level you want. Also, the Standby switch does NOT remove B+ high voltage (400Vdc) from the output tube plates as is traditional in most amps, it puts the tube in "cut-off" by more than doubling the negative bias voltage on the first grid (pin 5) from -31Vdc to -72Vdc. Another twist is that when you remove the input jack the amp automatically goes into the standby mode until you plug back in. This makes the amp absolutely quiet with nothing plugged into the input jack. This also means that you HAVE to insert a 1/4" plug into the input jack in order to bias the output tubes! Notice the attention to detail: Rubber O-rings in the chassis holes where the 12AX7 tubes are mounted and similarly isolated and padded EL34 tube retainers:

Image

Oh, here is a photo of the footswitch to keep this post on-topic!

Image

Anyway, this is an awesome amp at first look and I'll see how she does at this outside gig this evening.


Steve

Dude, great pics! thanks for those. Its a sharp looking rig for sure :D Can you explain how to bias it? Mainly where the test points are. I have biased my Spider Valve countless times so I know its a simple thing. I think I remember you saying you have played the spider valve? I have the 112 combo that has been modded a good bit and I think it sounds great. My only gripe with it is that it struggles to get a good ac/dc type of crunch. The high gain and clean are great though. I should have my Stage 60 early next week. I am PUMPED!! 8)

DrKarnivore
Posts: 68
Joined: Thu May 27, 2010 12:00 am

Wed Jun 30, 2010 9:07 pm

Brilliant work mate, thanks for posting this!

Incidentally, care to share your JCM800 setting?

pacAir
Posts: 39
Joined: Wed Jun 23, 2010 12:00 am

Wed Jun 30, 2010 10:07 pm

I'm glad you enjoyed the photos and post!

As far as the Spyder Valve goes, I have a MkII HD100 head. I recently repaired it (bad tube) and it seems to work flawlessly but I haven't made time to play through it. I want to take it out to a local jam I am a regular at to try it for real but I have to get "checked out" on it first!

I set the bias on the HT40 using a "bias probe" tool and measured the cathode current directly with that. There ARE several test points on the PC board in the area of the bias pots that must be the ones used to check bias and balance. However, I was in a hurry and didn't try biasing the amp with only a meter using these points:

Image

This photo was taken from the rear of the amp. The trimpot closest you (most rearward) in the photo is labeled PR1 and this is the Bias Balance adjustment. The trimpot towards the top of the photo (most forward) is labeled PR2 and this is the actual bias adjustment. There are 3 Test Points (pads on the PCB) to the left of the pots in the photo labelled TP10, TP13 and TP18. TP10 (connected to one end of the 1-ohm resistor) is the "Total Bias" measurement point. Measuring mV DC, each mV represents 1mA of cathode current.

Let's say you wanted to set each EL34 to 30mA of bias current. with your meter set to measure millivolts (mV), you would put your black meter lead on chassis ground and the red lead on TP10. Adjust trimpot PR2 to read 60mV (which represents 60mA, the total bias for both tubes). I BELIEVE (not sure) that TP13 and TP18 may be individual tube measurements and trimpot PR1 is adjusted to make these two test point measurements identical. Then you touch up the Bias then re-balance. I didn't use all of these test points so I am not sure how close I am. Remember, you MUST insert a 1/4" Phone plug or guitar cable into the input jack (and put the Standby switch in the "operate" position) to turn the tubes "On" so you can measure and set the bias. Turn the Master volume control all the down to prevent stray signals and noise from influencing your measurement.

I found the factory setting was about 25mA per tube (50mA total) and I only increased this a little bit. The amp might sound a little better at 30 or 35mA but I thought I would leave it in a safer "colder" range for now.


JCM800

I am not sure if I was being asked for control settings or the modifications I did to the amp.

The Amp: It is a 1984 Marshall 4104 50W 2x12 JCM800 combo. I bought it brand new in 1985 and modified the amp while it was less than a month old!

The Mods: I did 3 things to make the amp more usable for me in live music situations. I installed a small PC board with 2 DPDT relays on it. Each relay is switched by its own footswitch making connections through 2 1/4" phone jacks mounted on the rear chassis into which I plugged a dual footswitch (Roland) that had 2 1/4" mono Phone plugs on the end of the cable.

Relay #1 switches between 2 different Gain controls and two different Master Volume controls. I added an extra set to the front panel. THis is like a channel switch. I can preset each gain and its matching Master volume control differently then footswitch between them.

Relay #2 and footswitch takes a 25uF electrolytic bypass cap I added across the cathode resistor of the first input tube stage and switches it in and out of the circuit. This increases the gain (this acts as a foot-switchable boost) and makes the following stages louder and/or more over-driven.

The settings: Whatever I need and whatever sounds the best.

Yeah, I know it's a classic amp and you shouldn't mod them blah,blah,blah.... but I modified it to my tastes after I bought it brand new BEFORE it was a classic. My mods are classic as well!


Gotta run and get set up for the gig tonight! (Portland International Raceway in Portland Oregon, tonight 5:00pm to 8:30pm if you are in the area!)


Steve
Last edited by pacAir on Sat Jul 03, 2010 1:20 am, edited 1 time in total.

jshaffer23
Posts: 186
Joined: Sun Jun 13, 2010 12:00 am

Wed Jun 30, 2010 10:29 pm

pacAir wrote:I'm glad you enjoyed the photos and post!

As far as the Spyder Valve goes, I have a MkII HD100 head. I recently repaired it (bad tube) and it seems to work flawlessly but I haven't made time to play through it. I want to take it out to a local jam I am a regular at to try it for real but I have to get "checked out" on it first!

I set the bias on the HT40 using a "bias probe" tool and measured the cathode current directly with that. There ARE several test points on the PC board in the area of the bias pots that must be the ones used to check bias and balance. However, I was in a hurry and didn't try biasing the amp with only a meter using these points:

Image

This photo was taken from the rear of the amp. The trimpot closest you (most rearward) in the photo is labeled PR1 and this is the Bias Balance adjustment. The trimpot towards the top of the photo (most forward) is labeled PR2 and this is the actual bias adjustment. There are 3 Test Points (pads on the PCB) to the left of the pots in the photo labelled TP10, TP13 and TP18. TP10 (connected to one end of the 1-ohm resistor) is the "Total Bias" measurement point. Measuring mV DC, each mV represents 1mA of cathode current.

Let's say you wanted to set each EL34 to 30mA of bias current. with your meter set to measure millivolts (mV), you would put your black meter lead on chassis ground and the red lead on TP10. Adjust trimpot PR2 to read 60mV (which represents 60mA, the total bias for both tubes). I BELIEVE (not sure) that TP13 and TP18 may be individual tube measurements and trimpot PR1 is adjusted to make these two test point measurements identical. Then you touch up the Bias then re-balance. I didn't use all of these test points so I am not sure how close I am. Remember, you MUST insert a 1/4" Phone plug or guitar cable into the input jack (and put the Standby switch in the "operate" position) to turn the tubes "On" so you can measure and set the bias. Turn the Master volume control all the down to prevent stray signals and noise from influencing your measurement.

I found the factory setting was about 25mA per tube (50mA total) and I only increased this a little bit. The amp might sound a little better at 30 or 35mA but I thought I would leave it in a safer "colder" range for now.


JCM800

I am not sure if I was being asked for control settings or the modifications I did to the amp.

The Amp: It is a 1984 Marshall 4104 50W 2x12 JCM800 combo. I bought it brand new in 1985 and modified the amp while it was less than a month old!

The Mods: I did 3 things to make the amp more usable for me in live music situations. I installed a small PC board with 12 DPDT relays on it. Each relay is switched by its own footswitch making connections through 2 1/4" phone jacks mounted on the rear chassis into which I plugged a dual footswitch (Roland) that had 2 1/4" mono Phone plugs on the end of the cable.

Relay #1 switches between 2 different Gain controls and two different Master Volume controls. I added an extra set to the front panel. THis is like a channel switch. I can preset each gain and its matching Master volume control differently then footswitch between them.

Relay #2 and footswitch takes a 25uF electrolytic bypass cap I added across the cathode resistor of the first input tube stage and switches it in and out of the circuit. This increases the gain (this acts as a foot-switchable boost) and makes the following stages louder and/or more over-driven.

The settings: Whatever I need and whatever sounds the best.

Yeah, I know it's a classic amp and you shouldn't mod them blah,blah,blah.... but I modified it to my tastes after I bought it brand new BEFORE it was a classic. My mods are classic as well!


Gotta run and get set up for the gig tonight! (Portland International Raceway in Portland Oregon, tonight 5:00pm to 8:30pm if you are in the area!)


Steve
You seem to know your stuff man! Thanks for the info. You are the first one (I believe) to show how to bias these things. I am anxious to hear how it does at your gig! :D

trinity
Posts: 146
Joined: Sat Jun 26, 2010 12:00 am
Location: Patterson Ga USA
Contact:

Wed Jun 30, 2010 11:11 pm

awesome post pacAir !

Image

pacAir
Posts: 39
Joined: Wed Jun 23, 2010 12:00 am

Thu Jul 01, 2010 8:58 pm

Last night I played an outdoor gig (5pm to Dusk) using the HT-40 I repaired the previous evening. The gig went great (one guy gave the band a $100 tip!) and the HT-40 survived it all. This is the first important point to make ...survival. Since I had no previous experience with this amp I didn't know if I could trust it (not the design so much, mostly just this particular unit) so I brought a small back-up amp just in case (but did not have to use it, thankfully).

The amp performed well, however I am not coming to a complete opinion until I get a chance to use it for an indoor gig. Outdoor gigs (especially during the summer) are the toughest for a variety of reasons. Amps can bake in the sun for hours (like this one did, but thankfully the temperature was in the low '70s) and with nothing behind the amp to reflect the back energy, the audience in front only hears what comes out of the front of the speakers (so you waste almost 1/2 the energy the amp develops (with open-back cabs).

When using the HT-40 under these circumstances, I found myself wanting more power, more speakers and/or a bigger output transformer. I was running the Clean channel just below the audible distortion point on the input gain and turned up to about 7 or 8 on the volume control with the Master turned up past halfway. The amp sounded great but a little pushed without any reserve or headroom. When the gain channel was switched in it FELT like it was running out of gas even though I could play loud enough. I attribute this to the small output transformer. My best and most dynamic-sounding tube amps have large (sometimes massive) output transformers. There is simply NO SUBSTITUTE for IRON in your sonic diet. Appropriately sized transformers do make a difference. I think the sound of this amp would really "bulk-up" up with a larger output transformer.

Interestingly, I had a similar opinion of the Marshall Haze 40 combo ...It had some great tones but "wimped-out" when asked to deliver a lot of sound under difficult circumstances. The Haze 40 also has a relatively tiny output transformer, probably even smaller than the HT-40. The Blackstar is built to a noticeably higher standard of quality, though.

One thing I noticed about the HT-40 that surprised me. Even when running "balls to the wall" outside in the sun, the amp remained relatively cool. I attribute this to the widely spaced tubes, lower tube count, strategically placed convection-cooling holes in the chassis and the oversized cabinet that doesn't trap heat like a small cab does.

I'll be trying it out again tonight (without the extension cab) at a local jam I regularly go to to see how it does in a small club environment. Overall, I am still impressed by the HT-40. I was just fortunate to put it through its paces under some of the more difficult circumstances a small amp faces on its first live gig!


Steve


Last edited by pacAir on Wed Jul 28, 2010 2:29 am, edited 1 time in total.

pacAir
Posts: 39
Joined: Wed Jun 23, 2010 12:00 am

Sat Jul 03, 2010 12:35 am

I took the HT-40 Club to an indoor gig (prior to a jam) at a small club where we set-up on a stage in the corner. Because the regular bass player couldn't make it I ended up playing bass but got to hear my HT-40 after all as one of the guitar players elected to use my set-up over his. He was intrigued by the "new amp of the week" (I commonly bring a different amp to every jam). He was playing a boutique Strat-like guitar (very expensive and many thousands of dollars more than my normal American Standard Strat) and spent a few minutes adjusting the amp to his taste.

We were all quite impressed with his tone. It was killer when he got the sweet-spot for his guitar dialed in. The amp sounded great! I must have fielded questions from at least a half-dozen people who wanted to know what the amp was as it sounded great but they weren't familiar with the Blackstar brand. Several of them expressed a pending need of a new amp and will no doubt give some the new Venue models serious consideration.

Perhaps I will get a chance to play my HT-40 inside at the jam next Thursday! That is, of course, if I can fight the line-up of players who will want to try it out! It sure turned a few heads last night!


Steve

keithh
Posts: 14
Joined: Sat Jan 29, 2011 1:00 am
Location: The Wasteland

Sat Mar 12, 2011 5:30 pm

pacAir wrote:The info above states the the HTV-212 is made to match the HT-60 Stage model:

From the Blackstar Stage 60 Owner's Manual (online on their website):

Dimensions (mm): 715 x 586 x 278



Steve
715 x 586 x 278 ...combo
715 x 556 x 278 ...ext. cab

keith
Just got the HTV-212 and this is the same size as the stage 60 combo so it must be a mis print on the website

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