Bob Carver 180 Mono-blocks perform superbly

Thanks for the update mate. I'll certainly think about the upgrade in the near future. I ended up getting my pairs of matched sextant Sovtek kt88 tubes and the improvements in sound are vast to say the least! The music is more refined but most noticeably is a tighter, more detailed bass response. My input tubes being Telefunken 12AX7 with ribbed plates and Siemens 12AX7 with ribbed plates. Also have on hand some Trigon 12AT7 and Phillips 12AX7 to play around with!

Sovtek KT88s? I think those are even cheaper than the stock tubes, and they sound better than the stock? That's great. I have the Telefunken smooth plate 12AX7s.

I was a bit hesitant on spending $450 on a single EAT KT88 so went the other way around on a $30 Sovtek! Haha!

Gamble paid off as these slaughter the stock tubes in my system!

That's great you found affordable better KT88s. I read on thetubestore.com that the Sovtek has tight bass except for the very bottom end. What is your assessment of the very bottom end of this tube?

The EAT tubes are crazy expensive, and I've read they have reliability issues. I was considering Northern Electric KT88s which are "only" $198 per tube. Some very positive user reviews claim the NE is as good as the EAT tubes. The Carver's deserves the very best tube you can find.

http://www.thetubestore.com/Tubes/KT88-Tube-Types/Northern-Electric-KT88

Thanks again Drac on your thoughts. Yes, I think the Bobs deserve very good tubes plus cables. I have tried a few different IC's from my source to the Bobs with great results. I have a pair of Wywires Gold and also Jorma Unity RCAs. Having difficulty deciding which sounds better. Also the power cables into each Bobs are Wywires Juice II Blue which are moderately priced and sound great into the Bobs. Previously was using just stock power cables as the amps were running in.

Hi Dracule,
I'm ready to try out the Goldpoint. The existing knobs fit this GP? Or I have to order new knobs from GP?
TIA
Thuan

I checked the existing knobs and seem like 6mm or 1/4 in which match with GP shaft of 6mm. Ordered a pair.
Thx

Hi Thuan, I have the GP Mini-V Mono, 100kOm, in my amp.

http://www.goldpt.com/prices.html

The standard knobs on my Cherry 180 fit the GP. But my Cherry 180s may have different knobs than the current production. I would get the GP first and see if they fit your standard knobs.

Thanks Dracule,
I haven't open up the amp yet, so not sure how many joints that I need to desolder. Might need to buy some desolder wick to make the job cleaner/easier :)

Hi all,
I just replace the GP step attenuators just now :)
GP sent me the wrong (10K) instead 100K and take extra time to receive them. And it took me some searching to match the wires color code to new volume pot.
In short, this upgrade is dirt cheap and it worth every penny of $168 shipped :)
Sound is much more refined across spectrum.
Hope Carver still honor 7 yr warranty with my work on this GP replacement :)
Big thanks to Dracule on this mod
I still have no clue which cap you mentioned as I couldn't read the value of them (in placed with value at bottom)

Thanks for the feedback Thuan98.

I will most likely go for the GP attenuator upgrade as well.

I mentioned in an earlier post that I had upgraded my stock Electron KT88s to Sovtek equivalents with great results. I have now upgraded the Sovteks to Gold Lions others seem to recommend here. The results are even better with more refinement in the mids and highs. Plus a veil has been lifted it seems on the music with the Sovteks in place. So Gold Lions are definitely recommended for not a huge outlay.

I was also very fortunate to receive some EAT ECC 803S, 12AX7 equivalent.
These sound clearer and more transparent than the Telefunken 12AX7's I was using before. Music just has a more aliveliness to it now with the EAT/GL combo.

Hi Tuan89, I'm glad the GP worked out for you. It's the best affordable upgrade, better than tube rolling I think. The attenuator is the first thing the signal sees when it enters the amp, so a crappy volume pot will degrade the sound from the beginning no matter what you do downstream in the amp.

The output coupling caps are 0.22 uF (should be rated at >600V). You'll need 4 of them.

BTW, I've had GP in my amps for the past 2 years (had the amps for about 3 years I think). I've had zero problems (no hum, no pops, no tube hiss). Bias setting is stable once set. These amps are the most reliable tube amp I've ever owned, on par with the most reliable SS amps.

Vmhf, thanks for feedback on your tube rolling. I've wanted to try the Golden Lion KT88s, but hesitated because no one has reported about them with he Carvers. Now, I need to save up.

How much is a pair of EAT 12AX7s?

Hi Dracule,
I think there was someone else who mentioned the GL's earlier in this thread.
But I do have quite a few friends with other tubes amps that swear by them.

My HIFI dealer/friend uses top level Lamm mono blocks and has heard my Bobs with the stock Electron, Sovtek and Gold Lions. He noticed the transparency level and refinement of the Bobs the best he ever heard them!

EAT 12AX7's are pricy tubes at around $249 AUD each which is about $220 USD I gather. I put the Telefunkens back in for what appears a lusher smoother sound. Horses for courses as they say.

Just an update. The Goldpoint attenuators are now on the way!
I'll have my tech install them and might as well get him to do the cap upgrades too.

Will keep you guys posted!

Hi Vmhf, Which upgraded coupling caps did you decide to go with?

Hi Yoby,

I only received the Goldpoint attenuators yesterday so will be taking my Bob Carvers in to my tech's workshop next week.

I have not decided if I am going to get the caps upgraded at this stage.
Will have a chat to my tech and see what he thinks.

Cheers.

Thanks Victor.

Hi Dracule (or anyone can help me)
I'm ready to replace the coupling caps in mt VTA180 but unsure which ones.
I have pictures taken, would you help locate these .22mF caps?
Please email me at thuan20000@hotmail.com
TIA
Thuan

There's a good image of the under side wiring on the Carver LLC site > Products > Images > VTA 180 jpegs.

Thanks Vic,
My amp circuit laid out a bit difference.
I see 2 large Vishay with value on them as 100v 85 degree C (only these came with symmetric pair. Doesn't sound right?
How big are these caps? I also see a pair which noted 224J 630V - not sure which ones
I can send pic.

My amp is using caps denoted as Joule, not Farad
And nothing is match to .22mF :(
Any help would be appreciated
Regards

I try KT120s in Cherry 180 with good result :)
Produce stronger bass and larger soundstage, mid and high at least as good as Gold Lion KT88
I got green light from Carver staff to use these, he said KT120 will add extra 10-20 wpc. Still need time for break-in, I'm still around 5 hrs of break in period
Happy listening :)

How embarrass I am - Look further online to find how to read capacitor marking. the ones I found 224J 630V indeed .22mF @630V. The "J" is not Joule but it's 5% tolerance
I'm good now
Thanks all

Thanks for your updates Thuan98.

I had my Goldpoint attanuators installed a few weeks ago and all I can say the upgrade is 100% recommended.

The Bobs sounded fantastic with great tubes such as GL KT88's and Telefunken 12AX7 but the vol attenuators have lifted the Bobs to another playing field.

There is another level of clarity and resolution to be had that the stock volume attenuators were restricting.

I am still leaving the components as they are though as can't be happier with the sound I am getting now.

Anyone consider bypassing the volume attenuator?

I have just purchased Vcap CUTF, I wanted to ask how many caps do I need for the Feedback cap upgrade on the value of 2.2UF

I have seen some Duelund 2.2 VSF second ones sold for a pair at 200 dollars. So might buy this and see what happens.

Any other upgrades one can do the internals?

There is only one cap at 2.2 uF per amp

How about the power supply, any caps there we can change to better types?

Dragon_vibe, What's the status of your AtmaSphere MA2? How do they work in your hot humid climate?

Im still waiting for the build to complete. Prob Mid October as advised by Ralph.

Can anyone confirm the model types required for the Upgrades on the RCA input Sockets and the Speaker binding Post? the right ones to fit the chassis.

Hi all,
Carver site was down and I didn't save a copy of the user manual. Anyone know the fuses size of VTA-180, and how many?
I want to upgrade to high-priced fuse
BTW: Emotiva and Carver Tube no longer partnership - who will handle 7 yrs warranty on my amp? :(

Forget the warranty. Its gone.

has anyone bypassed the attenuator and wired direct? I have the GP in my amp but don't use the attenuator at all. I also switched out the 2 .22 caps in each amp with the Jupiter Beeswax HT - nice improvement in overall smoothness and resolution.

I kept mines in and upgraded the volume pot for the sake of flexibility to future upgrades if its ever needed. However if you do try to bypass it I would be interested in the gains you may notice?

Hi Guys,
I have picked up a pair VTA 180 with GP volume pots and did bypass the attenuator found the sound open up a little more, more resolution with clarity. I however found the deep bass is lacking and thinking of upgrade the output tube to kt120 or kt150. Can anyone here with such experience with KT150 please advise?

How do you bias the tube sets without an attenuator turned full counter clockwise?

Lacking deep bass, compared to what (speakers and amplifiers)? According to the manual Velodyne Room Optimization program I'm getting almost the same frequency depth on my Avalon Eidolons as compared to a pair of Hypex nCore 400s. The trace for the VTA 180s is slightly fatter around the 30-50Hz region. I personally prefer the what the VTAs are doing for general listening. The nCore are relegated to my little recording studio were the overall presentation is more useful than tubes.

Keep in mind we're getting into the subjectivity of our differing rooms. My listening room is on the large size with a vaulted ceiling, using more reflective diffusers and little in the way of absorption

anyone compare these with the Rogue m-180? thx!

Happy hollidays fellas!

I have had my cherries for a couple of weeks now and love them! Mine are in black sn#130 and 131. I am very intrested in switching out the volume pot but need to find a local person to do it. I live near louisville KY if anybody as a suggestion. Has anybody tried any of the other things like fuses or power chords? Also I am curious for the opinions on adding the KT-120's. From another carver site it is said to take them up to 260 watts at 8 ohms.

Thanks

Keep the volume pot and upgrade it to a better one. It is useful to have as a feature. Lets you experiment with DAC directly too.

Dracule1 - I have a pair of Bob's Cherry 180's. I elected to run my Sunfire Signature amp over the past year because the Cherries did not provide me the extra wattage/headroom I desired; I like to listen LOUD a lot of times. Over the past couple of days I cleaned up the Cherries, they just were collecting dust, literally, so after getting them all cleaned-up I reinserted them back into my system to see if I could live with the lower power output. I reinserted them because I was reading different threads on Audiogon about folks recently expressing their love for the Cherries, namely you sir.

After plugging them in...mmmmm, to hell with the extra head room for now, I think I may leave them in for a while. If I can get by the heat these beautiful tubes put off, but I don't remember them putting out as much heat as they are. When my money gets right, I plan on getting the two upgrades you spoke about 1) the GP attenuator 2) the V-cap .22 caps. I was thinking to do the copper instead of the tin caps. I'm not sure if the copper caps really sound better, but if anybody has any feedback one way or another I'd appreciate it.
Are there any other new upgrades for the Cherries?

...oh, and did you get matched pairs/quads of the .22 V-caps? Lastly, what tolerance (5%, 1%, 0.5%) should I get?

The 12ax7 & 12at7 Psvane tubes I installed 3 years ago have been the best of the few tubes I tried when I was doing the tube rolling thing. That was my 1st time with tube equipment.
I tried and ranked them this way:

1st Psvane - Well balanced and sounded just right. Not too this or too that.

2nd Mullard CV4004 & CV4024 NOS - Best Mids by far, but got tired of the effect after a while. Too too much of a good thing can wear on you.

3rd Gold Lion reissued - Brightest sounding of the bunch. Not waaay too bright, but my speakers can be finicky in the highs area to begin with.

4th Tung Sol reissued - Not a bad tube at all for the price; I think $20 each. I even might rank them above the Gold Lions depending on my mood that day. FWIW this tube had the highest gain of the few tubes I've tried.

All in all, I think I'm biased (lol) for a tube that is currently in production i.e. can be bought without having to hunt a set down here and there at some extremely marked-up price.
...oh, and I'm running Tung Sol KT-120's for my power tubes, even though the amps are set-up for the KT-88's. Back when I purchased them from Mr. Carver, he said it was cool to do and the KT-120's wouldn't harm the amps one bit. Now I'm curious if the cherries can handle the new KT-150's :-O

Heynow,

Was there a drastic improvement when you went to the kt-120's from the kt-88? From what I read it takes the power up to 260 watts. I know somebody that went to the 150's in the cherries but he had to have bob carver himself modify the power supply up the what is in the black beauty's. Carver charged him $1000 for the mod and $1100 for the tubes. From what I saw it didn't change the power ratings much.

When I bought the amp, direct from Bob, he gave me the option to have him send me the KT-88's that he normally sends or the KT-120's; his new company didn't come online 'til a short time later. Anyhow, I ended up having him send me the standard tubes and I ordered 12 KT-120's from another source. Once getting the amps home, I plugged in the KT-120's and they have been in pretty much the whole time. However, I did once after several months, try the KT-88's. The sound was actually a little warmer, but the tubes seem to be working very hard. What I mean is, I like to play my music relatively loud at times and with the KT-88's it looked like a fire storm raging in the tubes as the music played. These amps was/are my only experience with tube equipment, so that was kinda scary to witness. Maybe thats how power tubes regularly behave under serious music listening, but with the KT-120's the peak "flaming" is much less and conversely less stressful to see when enjoying your tunes. The only drawback with the KT-120's, is that you can barley see that the tubes are lit, even at night...and as we all know that's part of the appeal of having tubes...seeing the glow lol. As far as the warmth goes, I added some Mullard tubes (4004 & 4024) to the equation and that warmed and smoothed out the sound again.
Thanks for the info on the KT-150's. I think I'll stay with the KT-120's for now. My next move would be the upgrades on the gain/attenuator & 2caps on each amp; which Dracula1 spoke about earlier in this thread.

On one of my amps a couple of the kt-88 are going bad, the bias will max out at 100 where the other will max out at 140. Tax money will be for 12 kt-120's. I have already upgraded the front tubes to the Psvanes so I am hoping the combo will sound great.

I have the Psvane tubes also and go back and forth between them & the Mullards. What are your impressions of the Psvanes? Did you change both of the smaller tubes or just the 12ax7?
With the KT-120's plugged in, the min. you can bias the amp is 90 and the max is way passed the meter scale. I set mine sometimes at 90, sometimes at 150, but right now I have it set at 110. It depends on what mood I'm in and what music I may be listening to at the time.
I have had a total of two KT-120's tubes go south on me. The first one took out a resistor and I had to get a technician to help repair that. I contacted Bob and he and my technician, at the time, chatted about it and got the issue resolved. The second time one of the tubes went out, it was a tube in the other cherry amp, but it did not take out any resistor(s). It bears noting that the group of KT-120 tubes were not from Bob, they were from an online site. I subsequently got in contact with a local tube dealer (Upscale Audio) and bought & installed a whole new batch of 12 KT-120 tubes, just to put myself at ease. I haven't had any failures or problems since. The owner of Upscale Audio is a little high strung at times, but again, I've never had any problems with the KT-120's or the Mullard 4004's & 4024's or any other tubes a bought from him. The initial batch was purchased by a very well known online site. I'm not saying that site sales bad or bunk tubes in general, but it just so happened that I got a few tubes from them that took a Dive after only several months of service. I haven't used that site since though.

I have enjoyed the Ps vanes (12ax and 12at) both in my carvers and a vincent 236mk hybrid intergrated. They have a nice highs along with solid bass. The only others I have tried are the cheap stock tubes that came with each. I have read that Bob preferred the NOS telefuken. If I can find a good deal on some I might try a pair. Since my last post i tested my 88's using the sixth slot according to the owners manual and had a them test between 20 and 40. I then matched them up so each amp had the same added up number for all six and the bias was still low(110) vs the good amp(140). I must have something wrong with the one. I am going to try and contact emotiva and see what their tech says.